William B. Winborn

Sex steroid receptors in the stomach, liver, pancreas, and gastrointestinal tract of the baboon

Sex steroids have been shown to have a marked effect on the physiologic activities of the liver and the gastrointestinal tract. We performed autoradiographic studies using [3H]estradiol and [3H]dihydrotestosterone on male and female baboons for the purpose of identifying estrogen or androgen receptors, or both, in the liver, pancreas, stomach, and small and large intestines of baboons. Evidence for the presence of estrogen and androgen receptors was made apparent by high concentrations of silver grains over the nuclei of the cells of these tissues. Androgen receptors were largely confined to the nuclei of the smooth muscle cells of the tunica muscularis of the gut wall and the connective tissue interstitial cells of the liver, pancreas, stomach, and intestines. Estrogen receptors were prominent in the nuclei of the vascular smooth muscle cells in the liver, pancreas, gut, and the majority of the endocrine islet cells. These observations suggest that a variety of different cell types of the liver, pancreas, and gastrointestinal tract contain estrogen and androgen receptors that might modulate their cellular activities and influence several different physiologic processes.

Hyperplasia of the Gastric Glands after Small Bowel Resection in the Rat

One month and 7 months after proximal or distal small bowel resection, adult Sprague-Dawley rats show a significant increase in the number of epithelial cells of the gastric glands (total cells, P

Variation in the pattern of carbonic anhydrase activity in the cells of the gastric glands.

SummaryElectron microscopic cytochemical studies of cells of the gastric glands of the stomach reveal enzymatic sites for carbonic anhydrase activity within cells of the gastric glands of hamsters and humans not previously described. The localization of the carbonic anhydrase activity is made apparent by reaction products of lead salts. Numerous electron dense precipitates are evident as discrete circular and irregular profiles and are situated on the outer surface of the mitochondria of the parietal cells. Smaller amounts of the reaction products are seen within the granular endoplasmic reticulum, mitochondrial matrix and on the outer surface of the mitochondria of the chief cells.

Effect of small bowel resection on the gastric mucosa in the rat.

Male Sprague-Dawley rats (120 to 130 gm), unoperated, sham-operated, and those with a 50% resection of the proximal small intestine, were studied after periods of 3, 6, 9, or 12 months. Differences in body weight and in the surface area, thickness, volume, and cellular content of the gastric mucosa between these three groups of animals were compared and statistically analyzed. After an initial loss in body weight, animals with small bowel resection and sham-operated animals attained weights equivalent to unoperated controls. Comparison of the groups for mucosal surface areas of the body of the stomachs showed no significant differences at the 3-, 6-, or 9-month periods. However, 12 months after surgery, the mucosal surface area of stomachs from resected animals was significantly greater than in corresponding controls. At 3, 6, and 9 months after resection, the thickness and volume of the gastric mucosa and the epithelial cell populations (parietal and nonparietal) of the gastric glands were significantly greater than in controls. However, at 12 months, there was no significant difference in any of these parameters between the controls and the experimental animals. The DNA content of the gastric mucosa was significantly greater for animals with small bowel resection than for corresponding controls at 1 and 6 months after surgery. It is concluded that hyperplasia of the gastric glands exists for at least 9 months after proximal small bowel resection in the rat. This hyperplastic response may be responsible for the previously observed (N Engl J Med 272:509-514, 1965; Surgery 65:292-297, 1969) gastric hypersecretion associated with extensive small bowel resection.

Localization of progestin receptors in the islets of Langerhans.

Autoradiographic studies using the synthetic progestin [3H]ORG-2058 (16α-ethyl-21-hydroxy-19-nor-[6,7-3H]pregn-4-ene-3,20-dione) were conducted on female baboons. Numerous silver grains from the exposed photographic emulsion appeared discretely localized over the nuclei of the islets of Langerhans of the pancreases of baboons injected with [3H]ORG-2058. These observations indicate that islet cells might contain receptors for progestins and, combined with clinical observations by others, suggest that progestins have a direct effect on the islet cells and may modulate the release of insulin and/or other islet hormones.

Uptake and retention of3H-estradiol by gonadotrophs and lactotrophs in the pituitary glands of the guinea pig, hamster and gerbil

SummaryNuclear uptake and retention of3H-estradiol by luteinizing hormone (LH) and prolactin (PRL) cells was examined in three species of rodents (guinea pigs, hamsters and gerbils) using the combined techniques of immunocyto-chemistry and autoradiography. Castrated animals were injected with3H-estradiol and decapitated 1.5 h later. The pituitary glands were processed for thaw-mount autoradiography followed by conventional immunocytochemical staining for LH and PRL.3H-estradiol accumulated in more than 80% of the anterior pituitary cells in the gerbils, while only 33 and 22% of the cells accumulated3H-estradiol in the hamsters and guinea pigs, respectively. A varying percentage of immunoreactive LH and PRL cells in all three species were found also to contain binding sites for estradiol. Some LH and PRL cells in hamsters and guinea pigs and only some in PRL cells of gerbils were found to be devoid of grains. Quantitative analysis revealed that the number of grains per nucleus differed considerably from cell to cell. LH cells of guinea pigs accumulated much larger amounts of3H-estradiol than did the PRL cells, while the LH cells in the hamsters and gerbils accumulated only slightly more3H-estradiol than the PRL cells.These results confirm the previous observations in rats and baboons that demonstrated tremendous species differences in percentage of cells in the anterior pituitary gland that accumulated3H-estradiol. Also, these data suggest that there are functionally heterogeneous cell types among the LH and PRL cells in hamsters, guinea pigs and gerbils as has been previously demonstrated in rats and baboons.