The influence of different nutrients on plasma cholecystokinin levels in the rat

Summary Isocaloric and isovolemic amounts of protein (casein), fat (intralipid) and carbohydrate (saccharose) and an isovolemic control solution of water were administered intragastrically to conscious rats. The plasma CCK levels, determined by a sensitive and specific radioimmunoassay, showed an increment of 6.3±0.6, 2.7±0.5, 1.7±0.4 and –0.9±0.4 pM, respectively (basal value 2.5±0.3 pM). The threshold increment of plasma CCK to stimulate pancreatic enzyme secretion by exogenous CCK was found to be 1.5 pM. It is therefore concluded that casein is a potent stimulus for CCK secretion and pancreatic secretion, but that fat and even carbohydrate, although less potent, also produce a CCK increment above the threshold for pancreatic secretion.Supported by Grant IKW 86-16 from the Netherlands Cancer Foundation KWF.     

The influence of electrical stimulation of the rat brain on serum prolactin levels

Zusammenfassung Prolaktin wurde mittels Radio-immunbestimmung in Seren gemessen, die 30 und 60 min nach elektrischer Stimulation des Gehirns abgenommen wurden. Ähnliche Ergebnisse wurden in Kontrolltieren und elektrisch stimulierten Tieren erhalten. Die Serumprolaktinspiegel sanken, wenn die Elektroden in der präoptischen Region lagen. Ein vorübergehender Abfall wurde gemessen, wenn die Elektroden im ventralen, medialen Hypothalamus lagen. Keine Änderung im Prolaktinspiegel wurde gefunden, wenn die Elektroden im Neocortex lagen.

---

---

Acknowledgment. This work was supported by an NSF Research Grant, No. GB 27359. The authors appreciate receiving as a gift the rat prolactin RP-1-1 used for radioiodination and the rat prolactin RP-1 used as the standard from the NIAMD Rat Prolactin Hormone Distribution Program.     

The influence of chlorothiazide and tolbutamide upon intestinal serotonin levels in the sprague-dawley rat

Zusammenfassung Der Serotoningehalt der Schleimhaut im obern Duodenumteil, im mittleren Jejunum, im Ileumendteil und im Appendix von Sprague-Dawley Charles River Rattenmännchen wurde ohne Vorbehandlung und mit Chlorothiazid- und Tolbutamidvorbehandlung spektrophotofluorimetrisch bestimmt. Die Serotoningehalte für die 3 Gruppen vergleichbarer Gewebe waren ähnlich, was zeigt, dass die früher beschriebene Erhöhung des Serotoningehaltes der Schleimhaut nach Sulfamerazinvorbehandlung wahrscheinlich nicht mit einer unspezifischen Wirkung des Sulfonamidteils verbunden ist.

---

---

This study was supported in part by an award from the National Science Foundation toJ. H. Thompson, M.D., M.R.C.P.I., Department of Pharmacology, U.C.L.A. School of Medicine, Los Angeles, California 90024.     

The effect of glibenclamide on non-esterified fatty acid levels in the plasma of the severely alloxan diabetic rat

Zusammenfassung Zugabe von Glibenclamid bei Alloxan induzierten, stark zuckerkranken Ratten vermindert den Gehalt freier Fettsäuren im Blutplasma. Kein entsprechend antilipolytischer Effekt wurde bei Wiederholung des Experimentes beobachtet, wenn Chlorpropamid und Tolbutamid hundertfach stärker als Glibenclamid verabreicht wurde.     

Effect of carbon tetrachloride poisoning on the plasma levels of aspartate-aminotransferase isoenzymes in the rat

Riassunto Mediante frazionamento cromatografico su colonna di resina a scambio anionico, abbiamo potuto documentare nel siero di ratti intossicati con dosi diverse di CCl₄, incrementi assai significativi sia della componente mitocondriale che citoplasmatica della aspartato-aminotransferasi.     

Effect of agar on bradykininogen levels and esterolytic activity in rat plasma

Zusammenfassung Bei der Ratte führt intravenös injizierter Agar zur Senkung des Bradykininogengehaltes, Erhöhung derp-Tosyl-l-Arginin-Methylester (TAME)-Spaltfähigkeit, ferner zur Aufhebung der Sensibilität der Rattenhaut für Permeabilitätsstörungen durch passive kutane Anaphylaxie. Danach und nach in-vitro-Versuchen besteht die Möglichkeit, dass Bradykinin bei solchen Hautreaktionen eine Rolle spielt.

---

---

Work aided in part by grant no. 49-092-64-629, U.S. Army Research Office.     

The influence of long term estrogen treatment on plasma prolactin levels induced by ether anesthesia in ovariectomized rats

Summary 2 methods of continuous estrogen delivery, polyestradiol phosphate injection and implantation of Silastic capsules of estradiol-17 , in ovariectomized rats induced increases in plasma prolactin in the afternoon (15.00–17.00) beginning at 1 week and continuing for 4–8 weeks. In addition these methods of estrogen treatment potentiated the ether-induced increase in plasma prolactin in the morning (9.00–11.00) beginning on week 2 and continuing for 3–8 weeks. These results indicate that estrogen activates the mechanisms that cause an afternoon surge in prolactin before potentiating a morning elevation induced by ether anesthesia.Acknowledgment. This work was supported by NIH General Research Support, grant No. RR05384-14 to Wayne State University School of Medicine. The authors also with to express their appreciation to Mrs C. Van De Walle for her expert technical assistance in the prolactin radioimmunoassay, to Dr Richard R. Gala for his advice and support of this project and to the Rat Pituitary Hormone Distribution Program of NIAMDD for the generous gift of Rat Prolactin.     

Effects of thyroxine and exercise on the glandular and plasma levels of corticosterone in the male rat

Summary The results presented here demonstrates that the thyroid gland is essential for normal corticosterone production. They further show that exercise stimulates this production whether the thyroid gland is present or not. The release or metabolism of corticosterone seems dependent upon an intact thyroid gland since plasma levels of corticosterone are decreased during exercise if the thyroid is absent. The administration of thyroxine is not sufficient to renew these levels.     

The effect of salicylates on plasma fibrinolytic activity in the rat

Zusammenfassung Zufuhr von Kalium-Salicylat und Acetylsalicylsäure führte bei der Ratte zu einer Verminderung der Plasma-Antiplasmin-Aktivität (100 mg und 150 mg/kg). Somit erhöhen Salicylate in höheren Dosen die fibrinolytische Tätigkeit.

---

---

Acknowledgement. This study was carried out during the tenure (by J. C. R.) of a British Council-Sierra Leone Government Scholarship.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse

Summary Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

Time function of corticosteroid levels in the blood plasma of rats under the influence of222Rn inhalation

Summary The time function of corticosteroid level in plasma of rats under two different²²²Rn concentrations was investigated. Both curves show a maximum after 8 h. Whereas the higher activity of²²²Rn produces a second maximum after 5 days, the lower activity reaches its second maximum not before 9 days. From both time functions, a two-step mechanism in the intracellular control can be concluded.     

The influence of phenobarbital on the glycogen concentration of rat liver

Résumé On a constaté qu'une injection du phénobarbital provoque la diminution de la concentration du glycogène libre de 34% et la diminution du glycogène total de 22,6% seulement 24 h après leur injection. La répétition des injections du phénobarbital diminue le glycogène libre respectivement de 36% et de 28%, le glycogène lié de 46% et de 27%, et le glycogène total de 41% et 24%.     

Effect of acute administration of delta 1-tetrahydrocannabinol on beta-endorphin levels in plasma and brain tissue of the rat

Acute treatment with delta 1-tetrahydrocannabinol (delta 1-THC) elevated the concentration of beta-endorphin-like immunoreactivity (beta-ELIR) in plasma and in the hypothalamus, but not in the hippocampus of rats habituated to the injection procedure. These effects were not obtained with the psychotropically inert analog of delta 1-THC, cannabidiol. In animals that had not been habituated to the injection procedure, placebo treatment induced a decrease in hippocampal beta-ELIR.