Structural alterations in rat kidney proximal tubules perfused with fresh autologous serum

Two min of intraluminal perfusion of the rat proximal tubules with autologous serum induced marked ultrastructural alterations including extensive cytoplasmic vesiculation due to swelling of rough endoplasmic reticulum cisternae and occasional extrusion of nuclei and cytoplasm into the lumen. Within 4 min pronounced vesiculation of mitochondria was observed. These findings are consistent with the notion that serum-induced inhibition of proximal tubular fluid absorption is due to cell lysis, presumably mediated by complement activation.     

Lack of effect of colchicine on human neutrophil chemotaxis under agarose

Summary Human polymorphonuclear neutrophil chemotaxis under agarose was assessed following in vitro treatment of cells with colchicine. No inhibition of random migration or chemotaxis was detected. The discrepancy between these results and reports utilizing micropore filter assays could be due to the need for cell deformability in the latter.Supported by a grant from the Veterans Administration and Research grant AM 19349 from the NIAMDD, NIH.     

Absorption of iron from gut into blood: Sex- and time-related studies in rats

Summary As judged from 2-h blood level curves, adult female rats absorbed more Fe^II per cm² of gross duodenal mucosa than adult male rats. By contrast, the 2-h blood level curves per cm² of mucosa of proximal jejunum did not differ significantly in male and female rats although in both sexes, iron was absorbed more efficiently from the duodenum. This research was supported by grant RO1 AM 12381 from the National Institute of arthritis, Diabetes and Digestive and Kidney Diseases, National Institutes of Health.     

Modification of the action of pentagastrin on acid secretion by botulinum toxin

Summary I.v. botulinum toxin after 60–90 min abolished the dose-response relationship between pentagastrin and gastric acid secretion in anesthetized rats and guinea-pigs. The toxin reduced but did not abolish the acid stimulatory effect of histamine. As expected, the acid response to vagal stimulation was abolished and that to methacholine in rats was unaltered by the toxin.Acknowledgment. We are grateful to the generosity of Dr Edward J. Schantz, Food Research Institute, University of Wisconsin, for the botulinum toxin used. — This research was supported by NIH grant 1 RO1 AM 17125, The Secretion of Pepsin.     

Histochemical demonstration of differences in AMP deaminase activity in rat skeletal muscle-fibres

Summary The histochemical method for AMP deaminase confirms that rat slow-twitch fibres contain less AMP deaminase activity than fast-twitch fibres. However, the enzyme appears similarly localized in all fibre types.This study was supported by NIH grant AM 21617.     

Thymectomy modifies androgenizing effects of a testis transplant during critical period for neuroprogramming

Summary Thymectomy simultaneous with transplantation of a syngeneic testis from a littermate to Fischer 344 rats ameliorated the androgenizing effects of the testis transplant on ovarian morphology at 90 days of age.Supported by a Morseman Fellowship, NIH grants HD07097, AM21137 and NSF-RIAS grant SER77-06922.     

Tumorigenic activity of cloned polyoma virus DNA in newborn rats

Summary The proximal portion of the polyoma virus early region as well as the complete viral genome were cloned in pBR322. Recombinant plasmids induced tumors in newborn rats but only after linearization of the DNA by various restriction endonucleases.This work was financed by grant MA-6731 from the Medical Research Council and by a grant from the National Cancer Institute of Canada.     

Methemoglobin formation and reduction in relation to hemoglobin oxygen affinity

Summary It is suggested that although the high oxygen affinity hemoglobin (Hb LR) (143(H21)HisGln) with stabilization of R quaternary conformation is not more susceptible to the oxidizing effect of nitrites in vitro, in an in vivo situation where hemoglobin is partly deoxygenated, it might be more susceptible to methemoglobin formation due to higher oxidation and lower reduction rate.Supported by NIH grant No. 5 RO1 AM 20181-02 and VA grant No. 5455-002.Acknowledgments. The technical assistance of Ms Carol A. Perry is highly appreciated.     

Vitamin A antibodies: Application to radioimmunoassay

Summary A radioimmunoassay for serum vitamin A is described which can detect as little as 1 ng of retinol. The statistical characteristics of this assay are presented and its use in a nutritional experiment is discussed.This work was supported by United States Public Health Service grant 2 RO1 AM19716.     

Effects of sera and liver extracts from partially hepatectomized rats on liver slice DNA synthesis

Summary Sera from partially hepatectomized rats (PH) compared to sera from control rats (C) enhance liver slice DNA synthesis but depress kidney slice DNA synthesis. Alone, liver extracts from PH do not affect DNA synthesis; but adding sera to PH extracts stimulates, suggesting that sera and liver factors from PH may participate in compensatory growth.Acknowlegments. Supported by NIH, grant AM 15458, a grant from the Washington Heart Association, and Public Health Service, grant RR 5360 (Medical). The authors wish to express their appreciation to Angelina Vasques for technical assistance and Betty Mendelson, Patti Werr and Susan Dreux for secretarial help.     

Suppression of PHA-induced lymphocyte blastogenesis by concomitant presence of PPD in the culture

Summary PHA-induced lymphocyte blastogenic response was remarkably suppressed by the simultaneous presence of PPD in cultures of lymphocytes derived from individuals sensitized to PPD, but not affected by the presence of PPD when the cultures contained lymphocytes from an individual not sensitized to the protein. This double stimulation blastogenesis study with PHA and a specific antigen is feasible as a simple and rapid test to measure cell-mediated immunity to the antigen.Supported by United States grant USPHS Grant AM 27384.     

Spectral properties of methemoglobins prepared by the action of sodium nitrite and potassium ferricyanide

Summary Methemoglobin was prepared by the addition of sodium nitrite or potassium ferricyanide to oxy or deoxyhemoglobin. The spectral properties of these methemoglobins were studied before and after extensive dialysis. It is shown that the methemoglobin formed by sodium nitrite has substantial spectral differences in visible and Soret band compared to that formed by potassium ferricyanide. These differences are proportional to the excess of sodium nitrite only. This suggests that both methemoglobins are similar compounds.Supported by NIH grant No. 5R01AM 20181-03 and VA grant No. 5455-003.Acknowledgments. The technical assistance of Ms Carol A. Perry and the secretarial assistance of Ms Wanda Stewart are highly appreciated.     

Pharmacology and function of the myoepithelial cell in the eccrine sweat gland

Summary Both acetylcholine and a Ca-ionophore, A23187, are comparatively strong stimulants of eccrine sweat secretion in vitro. Nevertheless, the contraction of the secretory coil was seen only after stimulation with acetylcholine but not with alpha or beta adrenergic drugs or with A23187. It was thus inferred that the myoepithelial contraction may not be playing an indispensable role in the overall process of eccrine sweat secretion.Acknowledgment. The present study was supported by NIH grant 2R01AM 1625804.     

Isoelectrically focused carboxyesterases as a biological marker in chimeras

Summary Species-specific multiple forms of carboxyesterases (CE) were determined in zymograms obtained by isoelectric focusing (IEF) using homogenized wing zeugopodal tissues of chick, quail and quail-chick chimeras. The validity of the CE pattern of chimeric tissues was verified by the nuclear marker technique. Analytical IEF of CE was found to be useful for investigation of the origin of tissues in chimeras.Acknowledgment. This work was supported by grant AM21026.     

Effect of prolactin on fluid and NaCl absorption by the rat proximal and distal colon

Summary The rates of fluid and NaCl absorption are greater in the proximal than in the distal colon. Prolactin treatment caused significant increases in fluid and NaCl absorption in the proximal but not in the distal colon. This suggests that only the proximal colon region, where most of the fluid and sodium absorption takes place, is responsive to prolactin.This work was supported by N.I.H grant Ca-05388 and a Rockefeller Foundation Fellowship.The author is greatly indebted to Professor H.A. Bern for his advice and useful suggestions.     

Velocity gradient and contraction frequency of the pyeloureteral system

Summary An optical detection method, using video imaging, is used to quantitatively record the frequency and velocity profile of the renal pelvis of the rabbit. It is demonstrated that concentric waves originating at the periphery of the pelvis have an initial velocity of 3.2 cm/sec, accelerating toward the pelviureteral junction reaching a final velocity of 6.4 cm/sec.This work was supported by an NIH, grant No. AM 19366.     

Solubilization of prolactin receptor by a Zwitterionic detergent

Summary About 60% of the prolactin receptors were solubilized from rabbit mammary gland membranes by Zwittergent 3–12. The use of Zwittergent 3–12 resulted in increased sensitivity of the receptor assay and permitted use of ovine prolactin instead of human growth hormone in the receptor assay.Acknowledgments. This work was supported by grant AM 17476 from the National Institutes of Health.     

Uterine morphology and glycogen deposition of pregnant rats after clomiphene citrate treatment during preimplantation stages

Summary Clomiphene citrate did not induce glycogen deposition in the uterine luminal epithelium of pregnant rats as it did in ovariectomized rats. However, the drug did alter the epithelial morphology which may be a factor in its postcoital contraceptive action.Acknowledgment. The advice and guidance of Dr W.J. Bo are respectfully and gratefully acknowledged. This work was supported by USPHS grant AM 08029-6. The clomiphene citrate was supplied through the courtesy of the Wm. S. Merrell Co., Cincinnati, Ohio, USA.     

Acid excretion in young and adult Wistar Kyoto and spontaneously hypertensive rats

Summary Wistar Kyoto rats (WKy), the most widely accepted control for SH rats, show an inability to excrete acid appropriately when compared to another normotensive strain, SD. Coupled with the fact that KWy also develops sodium-sensitive hypertension, this makes them a more complex control than realized. At very young ages (<10-week-old), neither SH nor WKy show any deficiency in acid excretion.Acknowledgments. Supported by AHA grant 76 1019 and NIH grant AM 15458. The excellent secretarial help of Susan Dreux and Betty Mendelson is acknowledged.     

Gametes contain angiotensin converting enzyme (kininase II)

Summary The localization of angiotensin converting enzyme (ACE) in the gonads of the normal rabbit was studied by immunofluorescence and immunoelectron microscopy. The enzyme is present in the cytoplasm of testicular spermatids and of epididymal and ejaculated spermatozoa, and on the surface of follicular and tubal cocytes. These findings support the hypothesis that ACE has a role in gamete maturation and in fertilization.Acknowledgments. This study was supported by NIH grant AM36807 and by grants from the American Heart Association, the Joe and Emily Lowe Foundation, and the Dana Foundation. We thank L. Fernandez, B. Luders, I. Pawlowski, and K. Schwegler for technical assistance.