The present study involves the intracardial injection of iodinated ovine prolactin into albino rats and the autoradiographic demonstration of patterns of isotopic incorporation into ocular tissues, including the retina, choroid coat and ciliary body. Control procedures include the utilization of competitive hormonal binding, a comparison of the radioactive pattern in eyes after the injection of iodinated beef serum albumen and an autoradiographic evaluation of the thyroid glands of all groups. The competitive uptake of iodinated prolactin into ocular tissues also was examined by liquid scintillation spectrometry. In normal rats, radioactivity was localized over the cells of the choroid coat and ciliary body of all groups receiving iodinated prolactin. The inner segments of the photoreceptors were radioactive in rats at 15 min after injection, but were unlabeled at only 5 min after injection.

The present study examines the interaction of light damage to the retina and streptozotocin (SZ)-induced diabetes in male and female rats during the early development of the disease, when changes occur in the blood-retinal barrier and in pigment cell membranes. Exposure of rats to low illuminance was used to determine the relationship between photically-induced cell death and diabetes. Other groups of animals were exposed to a greater illuminance for shorter time periods (24 hours) in attempts to identify a specific post-treatment day for the effect of diabetes. Blood glucose levels were monitored to indicate the severity of the diabetes. Morphometric analyses and histopathologic observations demonstrated that the outer nuclear layer (ONL, photoreceptor nuclei) was reduced significantly in thickness in female rats exposed to light during a 9 day period after SZ injection, but was unchanged from the control groups when exposed beginning at 12 days after SZ treatment. Removal of the pituitary gland prior to SZ treatment and light exposure resulted in the survival of more photoreceptor cells and prevented the differential in ONL thickness observed between control and diabetic intact animals. Attempts to establish a period of greatest susceptibility of the diabetic retina to photic damage were unsuccessful, but results indicate that prior light history and/or shipment stress might be related to retinal damage from light exposure.

Melatonin and testosterone propionate (TP), either alone or in combination, were injected into groups of pregnant rats and into 2-, 6-, and 13-day-old female animals. Melatonin had an inhibitory effect on vaginal introitus and decreased the incidence of estrous smears, when injected during the early postnatal period. TP inhibited the canalization of the vagina in prenatally injected rats and caused precocious vaginal patency in animals injected on days 6 and 13. Female rats given TP alone showed persistent vaginal cornifîcation, while melatonin in combination with TP reduced the incidence of such persistent vaginal estrus and established irregular vaginal cycling.

5792,3,4 were observed only when large momts of radioactive C057 BI2 were added. Since the p k s consist of mixtures of proteins, identification of the specific proteins binding Co5' B12 cannot be delineated. Summary. A method was described for the separation of vit B12 binders in normal serum on a 15 X 4 cm DEAEcellulose column by stepwise elution with 0.005 M pH 8.0, 0.0175 M pH 6.3, 0.04 M pH 5.9, 0.1 M pH 5.8 and 0.4 M pH 5.2 sodium phosphate buffers.Two radioactive peaks appeared when 300 ppg C057 B12 per ml of serum had been added in vitro. With the addition of 2,000 ppg/ml of C057 BI2 to the serum, 5 radioactive peaks appeared.The occurrence of hereditary muscular dystrophy in an inbred strain of mice was first reported by Michelson et aZ( 1 ) , and in-