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Biomedical subjects

T Wenger

Publications and source records attributed to T Wenger.

At least 55 records · Page 3Linked to original sources
PubMed1981

Lack of difference in digoxin urinary excretion with two intravenous infusion rates.

Ten normal subjects were given 0.4 mg digoxin intravenously by bolus injection over 3 to 5 min and by constant-rate infusion for 1 hr. Urinary excretion of digoxin over the next 6 days, as measured by radioimmunoassay, was similar after both the rates of intravenous injection. In one subject, who excreted substantial amounts of digoxin reduction products, no difference was apparent in the amount of reduced metabolites excreted. These results are not in agreement with previous reports of an effect of intravenous infusion rate on urinary digoxin excretion.

Adult↗
PubMed1981

Ultrastructural immunocytochemical localization of substance P in the cat small intestine.

The immunocytochemical peroxidase-antiperoxidase technique was used to identify substance P (SP) in the cat small intestine at the ultrastructural level in the nerve plexuses. In the myenteric plexus the SP containing fibres form synapses with the other nerve terminals and run parallel to the circular muscle. The SP in these fibres is present in the vesicles of 80 to 120 nm or 150 to 250 nm in diameter. The results support the contention that SP containing nerve terminals are present in the enteric nervous system.

Animals↗
PubMed1980

Increase in the LHRH content of the organum vasculosum of the lamina terminalis and the medio-basal hypothalamus six hours after injection of kainic acid into the rat medial preoptic area.

The luteinizing hormone-releasing hormone (LHRH) content of the organum vasculosum of the lamina terminalis (OVLT) and that of the medio-basal hypothalamus (MBH) was studied 6 h after the injection of 1 microgram of kainic acid into the medial preoptic area (MPOA) at the day of diestrus. The injection resulted in a highly elevated LHRH content in the OVLT which exceeded that of the controls observed on the afternoon of proestrus. LHRH content in the MBH increased significantly, however, it did not reach the peak value of proestrus. No change occurred in luteinizing hormone (LH) and prolactin (PRL) levels, while serum follicle-stimulating hormone (FSH) values decreased significantly. The increased LHRH content of the OVLT and of the MBH might be due to an enhanced LHRH synthesis and/or to the stimulation of neurons which inhibit LHRH release.

Animals↗
PubMed1980

Immunohistochemical localization of substance P and ACTH-like activity in the central nervous system of the earthworm Lumbricus terrestris L.

The peroxidase-antiperoxidase (PAP) method was used for the immunohistological demonstration of substances P and ACTH in the cerebral and subesophageal ganglia of the earthworm, Lumbricus terrestris L. With rabbit antibody to substance P a positive immunoreaction was found in nerve cells smaller than the type A neurons of the cerebral ganglion. Their perikarya and nerve processes as well as their terminal enlargements in the synaptic zone were immunoreactive. ACTH-like activity was visible in a larger perikaryon type of the A neurons. Their nerve processes did not show any reaction. However, a part of the nerve terminals of the synaptic zone and a few neurons of type B of the cerebral ganglion, further some cells of the subesophageal ganglion reacted positively.

Adrenocorticotropic Hormone↗
PubMed1980

Circadian and cyclic LHRH variations in the organum vasculosum of the lamina terminalis of female and male rats.

The organum vasculosum of the lamina terminalis (OVLT) was investigated by immunofluorescence and quantitative electron microscopic methods, and its LHRH content was measured at intervals during the estrous cycle and in male rats. A well-defined circadian rhythm in the LHRH content was demonstrated in the OVLT. The highest value was observed on the day of proestrus with peaks at noon and in the late afternoon. The amount of LHRH was about the same in the male as in the female rats on the day of diestrus 1. The OVLT in both sexes contained LHRH-positive fibers and terminals, but less immunofluorescence was visible on the day of diestrus and in the male animals. Quantitative electron microscopic analysis shows that in the OVLT nerve terminals, abutting on the basement membrane, more granulated vesicles (80-90 nm in diameter) are present on the day of proestrus than on any other day of the cycle or in the male. Our results suggest that the OVLT may participate in some way in the control of the cyclic gonadotrophic function of the anterior pituitary and/or in the behavioral effect of sexual hormones.

Animals↗
PubMed1980

Immunocytochemical studies on the central nervous system of the earthworm, Lumbricus terrestris.

There are numerous aldehyde fuchsin (AF)-positive, neurosecretory cells of medium size (A cells) and a small number of large, AF-negative neurons (B cells) in the cortical layer of the cerebral ganglion. In the subesophageal ganglion, symmetrical groups of AF-positive cells lie ventrally. The peroxidase--antiperoxidase (PAP) method was used for the immunocytochemical study of substance P and ACTH in these ganglia. In addition, the presence of L-enkephalin and alpha endorphin could be confirmed. Using rabbit antibodies to substance P we found small immunoreactive neurons among negative A and B cells in the cerebral ganglion. The processes of these immunoreactive cells could be traced to the subcortical synaptic neuropil. With antibodies to ACTH, activity was visible in perikarya similar in size to A neurons. A part of the nerve terminals of the synaptic zone, some of the B neurons and further several nerve cells of the subesophageal ganglion reacted positively. Successive demonstration of substance P and ACTH on the same section showed that the two materials occurred in different cell types. Using antiopsin antibody in an indirect immunocytochemical test we observed strong reaction in numerous medium-sized perikarya and in nerve fibres of the synaptic zone of the cerebral ganglion, further in some neurons of the subesophageal and abdominal ganglia. In contrast to this result, the photoreceptor cells of the prostomium and cerebral ganglion were negative. Presumably, substance P is present in a perikaryon type hitherto unrecognized while ACTH and antiopsin reactions seem to be located first of all in A cells.

Adrenocorticotropic Hormone↗
PubMed1979

Short-term effect of the lesion of the organum vasculosum of the lamina terminalis on hypothalamic LH-RH and serum LH, FSH and prolactin in adult female rats.

The short-term effect of the mechanical lesion of the organum vasculosum of the lamina terminalis (OVLT) was investigated in 4-day cycling female rats. The lesions were performed on the 2nd day of diestrus, and the animals were killed by decapitation 30 h after the lesion. Serum LH, FSH and prolactin and hypothalamic LH-RH content of 3 different parts of the hypothalamus were determined with radioimmunoassay. OVLT lesion caused a significant increase in the LH-RH content of the mid-basal hypothalamus and in serum prolactin levels and a decrease in LH and FSH serum levels. The results support the view that the OVLT may play a role in the control of pituitary gonadotrophic hormone secretion.

Animals↗
PubMed1976

Ultrastructural changes in the vascular organ of the lamina terminalis following ovariectomy and hypophysectomy in the rat.

Based on quantitative evaluations it was observed that 4 and 14 days after ovariectomy, as well as 2 months after hypophysectomy, the larger granulated vesicles (70-110 nm in diameter) in the nerve terminals of the vascular organ of the lamina terminalis (OVLT) almost disappeared. The findings are consistent with the view that the OVLT may play a role in the control of pituitary gonadotrophic function.

Animals↗