Differentiation between neural and hormonal control of sexual behavior and gonadotropin secretion in the female rat.

The purpose of this study was to assess the relative roles of the neural and endocrine feed-back systems in the regulation of gonadotropin secretion and behavior in the female rat. Retrochiasmatic knife cuts were placed in animals which were tested for mating behavior on five consecutive days, subsequent to the development of cornified vaginal smears. A knife-cut control group was autopsied immediately after behavioral tests.

Effects of mating on serum LH, FSH, and prolactin and accessory tissue weight in male rats.

The literature reveals contradictory data regarding whether or not male release LH acutely following coitus. Since it has been shown that repeated mating increases accessory sex organ weight, suggesting induction of gonadotrophin release, it seemed of interest to reinvestigate the issue. Male rats were divided into two groups: the mated group was provided with frequent mating ("experiencing") trials; the unmated group served as cage controls which received no sexual contact throughout the entire experiment.

Biosynthesis of chondroitin sulfate. Role of phospholipids in the activity of UDP-D-galactose: D-xylose galactosyltransferase.

The role of phospholipids in the activity of UDP-D-galactose: D-xylose galactosyltransferase (galactosyltransferase I) from embryonic chick cartilage was investigated. Phospholipase C treatment of particulate galactosyltransferase I caused inactivation of this enzyme to the extent of 60 to 70% as well as hydrolysis of 75 to 80% of the membrane phospholipids. Addition of phospholipid restored activity to nearly control levels.

Effects of early treatment with antiserum to ovine follicle-stimulating hormone and luteinizing hormone on gonadal development in the rat.

Neonatal rats secrete considerable amounts of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) between 5 and 15 days of age. Antisera to LH and FSH were injected during this 11-day period in an attempt to study the importance of gonadotropins for functional development of the gonads. Autopsies at 15 days of age revealed normal ovarian follicular histology after either antiserum treatment, but antiserum to LH significantly retarded differentiation of interstitial tissue.

Stimulation of synthesis of free chondroitin sulfate chains by beta-D-xylosides in cultured cells.

Beta-Xylosides stimulate 2- to 6-fold the synthesis of glycosaminoglycans by three types of nonconnective tissue cells (RG-C6, NB41A, and rat hepatoma cells, and normal and simian virus 40 (SV40)-transformed normal human skin fibroblasts. The effect, which is specific for the anomeric linkage and the glycone, is observed in the presence and absence of puromycin. Beta-Xylosides may substitute for xylosylated core protein as initiators of synthesis of chondroitin sulfate chains.

Biosynthesis of chondroitin sulfate. Solubilization of chondroitin sulfate glycosyltransferases and partial purification of uridine diphosphate-D-galactose:D-xylose galactosyltrans.

UDP-D-Galactose:D-xylose galactosyltransferase, a membrane-bound enzyme which catalyzes the second glycosyl transfer reaction in the biosynthesis of chondroitin sulfate chains, has been solubilized and partially purified from embryonic chick cartilage. Solubilization was effected by treatment of a particulate fraction of a homogenate (sedimenting between 10,000 and 100,000 times g) with the nonionic detergent Nonidet P-40 (0.5%) and KCl (0.

Induction of ovulation by LH and FSH in the presence of antigonadotrophic sera.

Surges of both LH and FSH are secreted on the day of proestrus in the rat; both surges are blocked by pentobarbital (PB), WHICH ALSO BLOCKS OVULATION. The purposes of the present study were (a) to see if antisera to ovine LH or FSH would prevent ovulation from endogenously secreted rat hormones; (b) to see if exogenous ovine LH or FSH alone can cause ovulation in the presence of antiserum to ovine LH or FSH, when endogenous hormone secretion is suppressed by PB. Antisera were assessed for anti-OAAD or anti-hCG augmentation activity against ovine and/or rat pituitary hormones.

Nutritional knowledge, attitudes, and practices of high school graduates.

A mail survey was conducted to investigate the relationship between previous nutrition education in high school home economics classes and the present nutritional knowledge, attitudes, and practices of Ohio high school graduates. Findings revealed that young women previously enrolled in home economics courses with a unit in food, nutrition, and health did not achieve significantly higher scores in tests of nutritional knowledge, attitudes, and practices than did those who had not been exposed to such nutritional education. Attitudes toward food and nutrition were found to mediate the nutritional knowledge and practices of these high school graduates.

Stimulation of chondroitin sulfate proteoglycan production by chondrocytes in monolayer.

Chondrocytes in monolayer undergo morphological and biochemical changes which culminate in the establishment of cartilage nodules in vitro. Chondroitin sulfate or heparin, added to the culture media of these cells, stimulates the production of chondroitin sulfate proteoglycan over the entire period of culture with a maximum effect during the log phase of growth. In addition, a lag of 2-3 hours is required before an increase in sulfate incorporation into polysaccharide is observed.

Stimulation of synthesis of free chondroitin sulfate chains by beta-D-xylosides in cultured cells.

Previous studies have shown that D-xylose partially overcomes the puromycin inhibition of chondroitin sulfate synthesis in cultured chick embryo chondrocytes. Likewise, D-xylose stimulates chondroitin sulfate synthesis by limb bud mesenchyme cells previously treated with BrdU or limb bud cartilage cells treated with puromycin. The studies reported here show that p-nitrophenyl-beta-D-xylopyranoside and 4-methyl-umbelliferyl-beta-D-xylopyranoside cause a much greater stimulation than does D-xylose and are active at much lower concentrations.