Increased glucose uptake by intestinal mucosa and muscularis in hypermetabolic sepsis.

The purpose of the present study was to determine the following: 1) whether the sepsis-induced increase in glucose uptake was a generalized response along the entire length of the gastrointestinal tract; 2) the relative contribution of the mucosa and muscularis to the enhanced uptake; and 3) whether reducing intestinal blood flow would attenuate the elevated rate of glucose uptake. Hypermetabolic sepsis increased in vivo glucose uptake in all sections of the gastrointestinal tract (57-93%) except the stomach. The rates of glucose uptake per gram of tissue by the mucosa and muscularis were not different. However, because the mucosa accounted for the majority of the whole intestine mass, this layer was responsible for 76-78% of the glucose uptake by the entire small intestine. Intestinal blood flow, determined with the use of radiolabeled microspheres, increased by 127% in sepsis. In both groups, approximately 70% of the total intestinal blood flow was distributed to the mucosa. Somatostatin was infused to produce splanchnic vasoconstriction and decreased the sepsis-induced increment in intestinal flow to the mucosa and muscularis (38 and 54%), whereas the enhanced rate of glucose uptake was not altered. Somatostatin also produced a severe insulinopenia. These results indicate that hypermetabolic sepsis increases glucose uptake to a similar extent along the length of the small and large intestine and that the majority of this increase is due to an enhanced uptake by the mucosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Endotoxin-induced increases in regional glucose utilization by small intestine: a TNF-independent effect.

The purpose of the present study was to determine whether the lipopolysaccharide (LPS)-induced increase in glucose uptake was a generalized response along the length of the entire gastrointestinal (GI) tract and to assess the relative contributions of the mucosa and muscularis. The putative roles of tumor necrosis factor (TNF) and blood flow in the metabolic response of the intestine to LPS were also examined. In vivo glucose uptake (Rg) was determined for various segments of the GI tract under basal postabsorptive conditions and 3 h after intravenous injection of Escherichia coli LPS using 2-[14C]deoxyglucose. At this time, LPS-treated rats were euglycemic, and Rg was elevated in all sections of the GI tract (52-96%). In control animals, mucosal Rg accounted for 79% of the glucose uptake by the entire small intestine; LPS increased Rg in both the mucosa and muscularis and did not alter this relationship. The LPS-induced increase in intestinal Rg was not attenuated by pretreatment with TNF antibody. Cardiac output (CO) and intestinal blood flow, assessed using radiolabeled microspheres, were not different from control values 3 h after LPS. Blood flow to the muscularis was increased (120%) in all sections of the small intestine from LPS-treated rats. These results indicate that 3 h after a low dose of LPS, glucose uptake by the entire length of the GI tract was elevated, and the majority of increase was due to enhanced uptake by the mucosa, which was blood flow independent. Furthermore, the increased Rg was not dependent on elevations in plasma glucose, insulin, or TNF levels. However, an increased blood flow to the muscularis was associated with an elevated Rg in that region.

Morphological and histochemical study of the endometrical effects of ovral in the baboon.

In an effort to better understand changes induced by hormonal contraceptives, a group of female baboons were administered Ovral for a period of 9 months. During this time the endometrium was sampled by transcervical uterine biopsy from both the treated animals and from a control group. The biopsies were all obtained between 10 and 14 days of the treatment cycle or the normal menstrual cycle. The endometrial glandular cells from the treated animals exhibited an accelerated maturation compared with the controls. Ultrastructurally this was reflected by increased cell size, numerous long, slender microvilli on the apical membranes, and increased development of the Golgi complex. Differences were also observed in the predominant type of granule seen in the apical cytoplasm. After 3 and 6 months of treatment with Ovral, no significant differences were noted between groups or between animals within a group. However, after 9 months of treatment, the endometrium displayed differences from the earlier experimental groups as well as individual variations. The functional correlates of these observations are discussed and compared to human endometrium.

Histochemical and ultrastructural effects of enovid E on the endometrium of the baboon.

Endometrium from a group of baboons treated with the oral contraceptive, Enovid E, was studied histologically, histochemically and ultrastructurally, and compared to endometrium from normally cycling animals. All endometria were obtained by transcervical uterine biopsy between 10 and 14 days of the treatment cycle or the normal menstrual cycle. Histologically, no discernible differences between the control and experimental endometria were apparent. While observable differences were not evident between the endometrial alkaline phosphatase and succinate dehydrogenase activities of control and experimental animals, there was an increased acid phosphatase activity in the Enovid E-treated baboon endometrium. Ultrastructurally, the glandular cells of treated animals appeared to be more physiologically advanced than did those from the control endometria. These advances were evident from the prominent Golgi complex, increased development of the endoplasmic reticulum and increases in the size, number and complexity of mitochondria. The functional correlates of these morphological and histochemical observations are discussed and compared to human endometrial studies.

Fine structure of the corpus luteum of pregnancy in the gerbil (Meriones unguiculatus).

Corpora lutea from gerbils on days 1, 4, 8, 12, 16, 20, and 24 of pregnancy were studied electron microscopically. Similarly, luteal tissue from animals on the day of parturition and one day postpartum was studied (gestation: 24 days +/- 8-24h). Agranular endoplasmic reticulum increases in quantity through day 16 and thereafter is somewhat reduced. Granular endoplasmic reticulum and a population of small granules (type I) become abundant during late pregnancy and their possible role in the production and storage of relaxin is discussed. Luteal tissue undergoes a relatively rapid regression which begins on the day of parturition. Conspicuous in the regressing luteal tissue are large (type II) granules (possibly lysosomes), lipid droplets, leucocytic elements and macrophages. Functional correlates of these morphological findings are discussed.

Morphogenesis of the secondary palate in the Mongolian gerbil (Meriones unguiculatus).

This report describes the prenatal development and closure of the secondary palate in the Mongolian gerbil. Palatal shelves can be regularly observed on day 16, at which time they are directed vertically. On day 17, the shelves show an overall increase in size and length but remain vertically directed. During day 18, palatal shelves are usually in a state of transition from the vertical to the horizontal position. The process of palatal closure (fusion) occurs on the 19th day and is complete by day 20. The process of palatal formation and closure in the gerbil more closely resembles that of the rat and rabbit than that of the mouse.

The effects of prostaglandin F2alpha on the fine structure of the corpus luteum of the pregnant hamster.

Corpora lutea (C.L.) from normal and prostaglandin-treated pregnant hamsters were examined by light and electron microscopy. Luteal cells from pregnant control animals were hypertrophied and contained an abundance of agranular endoplasmic reticulum (AER) suggesting steroidogenic activity. Animals which were injected on day 4 of pregnancy had ovulated by the third day following the injection, hence, two generations of corpora lutea were present in the ovary. Luteal cells from the "old" C.L. of pregnancy underwent a progressive degeneration during the four days following the single prostaglandin injection, whereas, cells from "new" C.L. appeared viable in most respects. The presence of aggregated platelets in both "old" and "new" C.L. was noted. It is suggested that the "new" C.L. are responsible for the rebound of plasma progesterone reported in previous investigations three days following prostaglandin treatment in pregnant hamsters.

Fine structure of the corpus luteum of the autografted ovary in the rat.

The rat ovary has been transplanted successfully to subcutaneous tissue areas by several investigators. Light microscopy has revealed that corpora lutea in ovarian autografts are formed by luteinization of intact follicles and contain entrapped ova. In the present study, corpora lutea from autografted ovaries in castrate rats were obtained at metestrus and examined electron microscopically to determine whether their cellular morphology correlated with the normal progesterone levels in these animals. Cellular features usually accepted as regressive were apparent. The findings suggest either structural luteolysis is occurring before functional luteolysis or that the adrenal has increased steroidogenic activity in the castrate with ovarian autografts to account for the normal progesterone levels.

The effects of prostaglandin F2alpha on the fine structure of the corpus luteum of the hysterectomized guina pig.

Luteal cell fine structure was studied in hysterectomized control and hysterectomized, prostaglandin-treated (1-5 days) guinea pigs. In hysterectomized control animals, luteal cells were hypertrophied and were characterized by an abundance of agranular endoplasmic reticulum (AER) suggesting steroidogenic activity. With one day of prostaglandin treatment, little change in the cytological appearance had occurred. After two, or three days of treatment, cells showed a decrease in size and an apparent increase in the number of lipid droplets. Following four days of prostaglandin treatment, luteal tissue was characterized by the presence of large amounts of collagen in the intercellular spaces and by the invasion of fibroblasts. Areas of degenerating luteal cells with numerous myelin figures and lipid droplets were observed. After five days of prostaglandin treatment, most of the luteal cells had undergone extensive luteolytic changes. Typically they contained coalescing lipid droplets, myelin figures and crystalloids, and were surrounded by collagen fibers. These observation suggest that prostaglandin F2alpha does effect structural luteolysis in this species in the absence of uterine tissue.