Influence of light on the plasma gonadotropin concentrations in the newborn rat.

The physiological increase in plasma gonadotropin (LH and FSH) levels in newborn rats is indisputably influenced by light. Permanent illumination accentuates this increase, whereas darkness decreases it in 16-day-old female rats. In male rats of the same age, only permanent illumination was tested with the same results.     

Changes in plasma enzyme concentrations in response to blood substitution with perfluorocarbon emulsion in the conscious rat

The effects of near total blood replacement with the proprietary perfluorocarbon (PFC)-based emulsion, Fluosol-DA 20%, on plasma concentrations of 2 enzymes, lactate dehydrogeanse (LDH) and alkaline phosphatase (ALP), have been examined in conscious, chronically catheterized rats. A pronounced fall in both plasma LDH (p less than 0.05) an ALP (p less than 0.01) occurred in response to exchange-transfusion. However, at 6 h following blood replacement, plasma concentrations of both enzymes had risen to values significantly greater than those measured immediately before perfusion. The observed changes in plasma LDH and ALP after blood replacement with Fluosol-DA indicated alterations in normal functioning of tissues from which these enzymes originate.     

Effect of an oral contraceptive on plasma dehydroepiandrosterone concentrations

Summary Plasma concentrations of dehydroepiandrosterone were measured in women by radioimmunoassay. It was found that a single dose of a combination type oral contraceptive Minovlar^® reduced dehydroepiandrosterone concentrations significantly.We would like to thank Dr M.L'E. Orme for helpful discussions.     

Influence of phenylbutazone on bile flow in the rat

Summary Phenylbutazone, a well-known enzyme inducer, at a dose of 80 mg·kg^–1 once daily for 8 days increases liver weight and bile flow expressed per g of liver (p<0.01). The bile salt secretory rate is not increased.     

Effect of food and light schedule on bile flow in the rat

Summary In the rat after food intake, whether during the dark or light period, bile flow increases. Food intake seems to be a major factor in the circadian rhythm of bile secretion.     

Effect of food and light schedule on bile flow in the rat

In the rat after food intake, whether during the dark or light period, bile flow increases. Food intake seems to be a major factor in the circadian rhythm of bile secretion.     

Effects of surgical sympathectomy on catecholamine concentrations in the posterior pituitary of the rat

Summary Approximately one-third of the norepinephrine in the posterior pituitary of the rat is contained in terminals of sympathetic nerves which originate in the superior cervical ganglia; the remaining norepinephrine and dopamine appear to be in nerves of central origin.This study was supported by USPHS grant NS09174. R.H. Alper is a predoctoral student supported by USPHS Training grant GM07392. K. T. Demarest is supported by NIH Fellowship NS06026.     

Taurine concentrations in the aqueous humor and plasma of anesthetized rabbits

Summary Aqueous humor taurine concentrations were found to be significantly higher (p<0.01) than that of the plasma in anesthetized rabbits. Topical application of 2 mg terbutaline lowered intraocular pressure (p<0.001), but did not alter aqueous taurine content.Supported by National Eye Institute grants Nos EY05430 (JMR) and EY02156 (DEP).Acknowledgments. We thank Dr J. Gintautas, this institution, for translating reference 18 and Dr S. Y. Schmidt, Massachusetts Eye and Ear Infirmary, for valuable advice.     

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.

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

Electrophysiological evidence for the action of light on the pineal gland in the rat

Résumé La lumière a un effet inhibiteur sur l'activité électrique tonique spontanée de l'épiphyse du rat, enregistrée dans l'obscurité. Les éléments photosensibles se trouvent au niveau des yeux. Le fait que la réponse a été bloquée par le chlorure de hexamethonium suggère qu'elle est transmise à l'épiphyse par les nerfs sympathiques postganglionnaires.     

Effects of bromocriptine on plasma testosterone and gonadotropin levels and testicular lipid fractions in adult rats

Summary Bromocriptine treatment of adult male rats resulted in a decrease in testicular testosterone (T) content and a reduction in plasma T levels. This was accompanied by increase in testicular total lipids and cholesterol and depletion of testicular phospholipids.Acknowledgments. We thank Dr R. L. Elton of Sandoz Pharmaceuticals for provision of CB-154. This work was supported by the Rockefeller Foundation, New York, NY, and by NIH grants HD 12642 and P-30 HD 10202 (Radioimmunoassay Core).