The effect of a bradykinin antagonist on vasodilator responses with particular reference to the submandibular gland of the cat

A bradykinin analogue, D-Arg[Hyp3, Thi5,8, D-Phe7]-Bk, antagonized the vasodilator effect of bradykinin injected close-arterially in the submandibular salivary gland of the cat, without affecting that due to acetylcholine or nerve stimulation. The same analogue also antagonized the hypotensive response to bradykinin injected intravenously in cats and rabbits. We conclude that functional hyperaemia in the submandibular gland of the cat is not due to the release of bradykinin by salivary kallikrein.     

The effect of a phorbol ester upon the cholinergic regulation of potassium permeability in the rat submandibular gland

Acetylcholine releases calcium from cytoplasmic stores and permits an influx of calcium in salivary acinar cells. The resultant rise in [Ca²⁺]_i causes an increase in potassium permeability which is an important part of the secretory response. We have investigated the effects of 12-0-tetradecanoyl phorbol-13-acetate, a potent activator of protein kinase C, upon this regulation of potassium permeability in superfused pieces of rat submandibular salivary gland. This compound inhibited the initial [Ca²⁺]_o-independent component of the response of acetylcholine but had no effect upon the subsequent [Ca²⁺]_o-dependent phase. This compound does not, therefore, appear to inhibit receptor-regulated calcium influx.     

Demilune cells of the cat submandibular gland; an unlikely source of kallikrein

The functional significance of kallikrein in the salivary gland remains unclear partially because of uncertainty over its precise cellular localization. Kallikrein was thought to originate in acinar cells, until recent evidence from cat and rat localized it primarily to the ducts. The possibility that salivary kallikrein may also be located in demilune cells was investigated in this study. - The total kallikrein content of cat submandibular glands was found to be substantially reduced by sampathetic nerve stimulation; whereas parasympathetic stimulation had no significant effect. These biochemical findings did not correlate with morphological studies that revealed almost complete depletion of the demilune cells secretory granules after stimulation of either division of the autonomic nerve supply. This lack of correlation makes it unlikely that kallikrein is present in the demilune cell secretory granules.     

Amiloride impairs the cholinergic regulation of potassium permeability in the human sweat gland but not in the rat submandibular gland

Potassium permeability was monitored in human sweat glands and rat submandibular glands. Acetylcholine increased permeability in both tissues and the responses consisted of transient, calcium-independent and sustained, calcium-dependent components. Amiloride, a drug which inhibits Na⁺?H⁺ countertransport, impaired the regulation of potassium permeability in sweat glands but not in the submandibular gland. It is suggested that the stimulus-permeability coupling process in the sweat gland may be sensitive to the lowering of internal pH.     

Demilune cells of the cat submandibular gland; an unlikely source of kallikrein

Summary The functional significance of kallikrein in the salivary gland remains unclear partially because of uncertainty over its precise cellular localization. Kallikrein was thought to originate in acinar cells, until recent evidence from cat and rat localized it primarily to the ducts. The possibility that salivary kallikrein may also be located in demilune cells was investigated in this study. — The total kallikrein content of cat submandibular glands was found to be substantially reduced by sampathetic nerve stimulation; whereas parasympathetic stimulation had no significant effect. These biochemical findings did not correlate with morphological studies that revealed almost complete depletion of the demilune cells secretory granules after stimulation of either division of the autonomic nerve supply. This lack of correlation makes it unlikely that kallikrein is present in the demilune cell secretory granules.Acknowledgment. This study is made possible through the Dean's MRC grant number MD-3489 to the College of Dentistry, University of Saskatchewan.Authors wish to thank Mr. D. Duncan, Dept. of Oral Biology and D. Mandeville of Medical Photographic Services for technical assistance.     

Immunohistochemical evidence that tumors elicit the synthesis of estrogen receptors in the submandibular gland of female rats

We have demonstrated the presence of estrogen receptor mRNA and the mature protein in the cytoplasm and nucleus, respectively, of a 9,10-dimethyl-1,2-benzathracene-induced submandibular gland tumor in female rats. We have previously shown that progesterone receptors are also present in human salivary gland tumors. These results suggest that endocrine therapy may be effective in treatment of submandibular gland tumors.     

Einfluss von synthetischem Bradykinin und Kallidin auf die Chemoreceptoren der Gefässe der hinteren Extremität der Katze

Summary The hindlimb of cat was separated from the body, the sciatic nerve remaining intact, The separated hindlimb was perfused through the femoral artery with tyrode solution. Synthetic bradykinin and kallidin injected into the femoral artery elicit vasoconstriction in the hindlimb, reflex on the systemic blood pressure, and stimulation of respiration. We assumed the cause of this reflex to be general sympathetic excitation through stimulation of chemoreceptor cells in the blood vessels of the hindlimb of the cat.     

42K spaces in submandibular gland of early postnatal rats: effects of carbachol and transport inhibitors

Summary Equivalent spaces of⁴²K were measured in fragments of the submandibular gland of 1-, 7-, 14- and 21-day-old and adult rats in the absence and presence of carbachol and the transport inhibitors ouabain and furosemide. The results indicate that the⁴²K space was increased by carbachol in an ouabain-sensitive manner at all ages studied and that part of the secretagogue-stimulated K uptake occurred by way of a furosemide-sensitive transport system in the latter part of the postnatal period and in the adult.     

Differential effects of prostaglandins and isoproterenol on cAMP content and Na,K pump activity in rat submandibular acini

Summary The -adrenergic agonist isoproterenol and prostaglandins E₁ and E₂ (but not F₂) increased the cAMP content of rat submandibular acini in vitro, but only isoproterenol enhanced ouabain-sensitive⁸⁶Rb (K) uptake. These findings suggest that cAMP is not involved in the activation of the Na, K pump in salivary cells.     

Stimulation of glycoprotein secretion in dispersed rat submandibular gland acini by cystic fibrosis serum

Summary Acini were enzymatically dissociated from rat submandibular gland and their mucous glycoproteins radiolabelled with¹⁴C-glucosamine. Sera from cystic fibrosis patients stimulated the release of labelled TCA/PTA — insoluble material from the cultured acinar cells to a significantly higher degree than did control sera.This work was supported by the Canadian Cystic Fibrosis Foundation and the Sellers Foundation.     

Gefässkonstriktion durch synthetisches Bradykinin und ihre pharmakologische Beeinflussbarkeit

Summary The divided hindlimb of the cat was perfused through the femoral artery with tyrode solution. Synthetic bradykinin administered via the artery elicits a vasoconstriction,- and-sympathicolytics decrease the vasoconstriction, cocain and guanethedin emphasize it, whilst iproniacid and reserpin have no influence on it. It is assumed that bradykinin acts directly on adrenergic structures of the vessels of the hindlimb of the cat.     

Cellular and subcellular localization of3H-diethylstilbestrol in the pituitary,oviduct and uterus of the female rat

Summary Female rats were injected with³H-diethylstilbestrol. The pituitaries, oviducts, and uteri were removed and processed for autoradiography. The nuclear uptake and retention in these tissues appeared similar to that seen after the injection of³H-estradiol except in the pars nervosa of the pituitary gland.This study was supported by US PHS Career Development Award No. NS00164 and PHS Grant No. NS21933.     

Wasting syndrome in neonatal mice after administration of salivary gland homogenate

Summary A wasting syndrome, similar to that occurring after cortisol treatment, was induced in neonatal mice by means of the daily i.p. administration of salivary gland homogenate: 24 h after a single injection of the, homogenate, profuse cell necrosis was observed in the thymic cortex, 48 h later the cortex was devoid of lymphocytes. It is hypothesized that the submandibular glands of mice contain substance which are capable of inducing a cortisol-like effect.We should like to thank Miss Angela Würfler for her careful technical assistance.     

Peroxidase activity and thiocyanate accumulation in salivary glands

Summary Salivary glands with high, low, or no peroxidase activity do not differ in [S¹⁴CN^–] after the i.v. injection of KS¹⁴CN, nor do the glands differ from blood and muscle in [S¹⁴CN^–]. The content of SCN^– in a salivary gland does not mirror the gland's participation in the peroxidase-mediated antimicrobial mechanism.     

Autoradiographic studies on RNA synthesis and transport in the Salivary gland ofLygaeus sp. (Hemiptera-Lygaeidae)

Summary Autoradiographic studies using³H-uridine in the salivary gland of adultLygaeus sp. were carried out. The gland cell nuclei, particularly the multiple nucleoli, are the sites of incorporation of the label exhibiting RNA synthesis. The labelled molecules (RNA) are transported to the cell cytoplasm and then into the gland lumen in which no turnover of the radioactivity is observed.I am grateful to my teacher, Prof. P. S. Ramamurty, School of Life Sciences, University of Hyderabad, for his constant inspiration. Grateful acknowledgement is made to Prof. J. P. Thapliyal, Dept of Zoology, B. H. U. for encouragement and to Dr Om Prakash, Dept of Biochemistry, B. H. U. for his valuable criticism.     

Lokalisation zusätzlicher RNS-Synthese in Trypsin-behandelten Riesenchromosomen vonChironomus thummi

Summary After injection of buffered trypsin into nuclei of salivary gland cells ofChironomus thummi, the existing puffs in the giant chromosomes are enlarged. Autoradiography shows an increase in RNA synthesis of approximately 3-fold in these puffs. It is argued that histones in puffed chromosome segments are in a structural state that renders them unable to prevent RNA synthesis and at the same time causes them to be attacked earlier by trypsin.     

Further evidence for the dissociation of digoxin-like immunoreactivity from Na+, K+-ATPase inhibitory activity

Summary The effects of adrenalectomy or nephrectomy, carried out one hour previously, on the levels of endogenous digitalis-like factors were determined in rat plasma. Factors were assayed by digoxin-like immunoreactivity and direct Na⁺, K⁺-ATPase inhibitory activity. Digoxin-like immunoreactivity significantly decreased one hour after bilateral ablation of adrenals, while Na⁺, K⁺-ATPase inhibitory activity remained unaltered. There were no changes in either activity one hour after bilateral nephrectomy. These results suggest that digoxin-like immunoreactivity may be derived from the adrenal gland or under adrenal control and the major substances detected by digoxin-like immunoreactivity and direct Na⁺, K⁺-ATPase inhibitory activity may be different.     

Angiotensin II in the hippocampus. A histochemical and electrophysiological study

Summary The presence of the renin angiotensin system in the hippocampus is shown by immunohistochemistry. Intra- and extra-cellular recordings revealed that angiotensin II and III excite CA 1 pyramidal cells by disinhibition. The effect is antagonized by [Sar¹, Thr⁸]-A II.This work was supported by grant Nos 3.271.78 and 3.396.78 of the Swiss National Science Foundation and research grant HL-24112 from NIH. T. Inagami was a visiting scientist of the Roche Medical Research Foundation.     

On the contribution of haemolymph to the salivary proteins of the red cotton bug,Dysdercus koenigii F. (Heteroptera,Pyrrhocoridae)

Summary Polyacrylamide gel electrophoresis of haemolymph and the salivary gland of adult maleDysdercus koenigii has been carried out. The presence of common bands in the electropherograms of the salivary gland and haemolymph shows the possible elaboration of haemolymph protein into the salivary glands as also evidenced by leucomethylene blue incorporation into the salivary gland lobules. The results are discussed in the light of our present state of knowledge.I wish to acknowledge the financial support from the C.S.I.R., New Delhi, India. Grateful acknowledgements are made to Prof. P.S. Ramamurty for encouragements, and to Zoology Department, Banaras Hindu University for the working facilities.     

Chemical defense in the three European species ofCrematogaster ants

The composition of the Dufour gland of the antC. scutellaris has been reinvestigated by gas chromatography/mass spectrometry. The major components of the gland are (2E,5E,12Z)-4-oxoheneicosa-2,5,12-trien-1-ol acetate (1a) its ¹⁴ and ¹⁶ double bond isomers (1b and1c), and the corresponding (Z,Z)-dienes5a and5b, all containing an acetylated C₂₁ chain. The previously proposed structures1d, 1e, and5c, which are based on an homologous acetylated C₂₃ chain, correspond to minor derivatives present in the gland. Traces of acetylated C₁₉ homologs, tentatively identified as1g-1i, have also been found. The Dufour gland contents of the two other EuropeanCrematogaster species have also been studied.C. auberti is very similar toC. scutellaris in producing mainly1a, 1b and1c, together with the same higher and lower homologs, but it lacks the dienic derivatives5, whereasC. sordidula contains essentially the acetylated C₁₉ compounds1g, 1h, and1i, accompanied by acetylated C₁₇ homologs.