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Biomedical subjects

M Majewski

Publications and source records attributed to M Majewski.

At least 73 records · Page 4Linked to original sources
PubMed1994

NO-synthase-containing neurons of the pig inferior mesenteric ganglion, part of them innervating the ductus deferens.

The presence of nitric oxide-synthase (NOS) in neurons of the porcine inferior mesenteric ganglion (IMG) has been investigated. A minority (about 1-3%) of the neurons were immunoreactive (IR) for NOS, the vast majority of which stained for neuropeptide Y (NPY) but not for tyrosine hydroxylase (TH). A small subpopulation of prevertebral neurons, 1% of which stained for NOS or NADPH-diaphorase (NADPHd), projected to the ductus deferens, as demonstrated by retrograde tracing. Within the wall of the ductus deferens, NOS- or NOS/NPY-IR nerve fibres were found to innervate the smooth muscle or were closely associated with blood vessels. It is therefore suggested that nitric oxide might be involved in the regulation of local blood flow and muscular tone in the wall of the pig ductus deferens.

Amino Acid Oxidoreductases↗
PubMed1994

Immunohistochemical localization of neuropeptides in nerve fibers of the porcine vagina and uterine cervix.

The distribution of vasoactive intestinal polypeptide, substance P, Met5-enkephalin-Arg6-Gly7-Leu8, neuropeptide Y, calcitonin gene-related peptide and bombesin/gastrin releasing peptide was studied immunohistochemically in nerve fibres supplying the vagina and uterine cervix of sexually immature pigs. Nerves containing neuropeptide Y- and Met5-enkephalin-Arg6-Gly7-Leu8-immunoreactivity were particularly numerous in the uterine cervix and vagina. Vasoactive intestinal polypeptide- and and calcitonin gene-related peptide-containing nerves were less numerous, whereas the bombesin/gastrin releasing peptide- and substance P-immunoreactive nerves were scarce in these organs. Generally, the immunoreactive fibres, nerve networks or bundles were distributed under the serous membrane, among smooth muscle of muscular membranes, in the submucosal layer and under the luminar epithelium of the uterine cervix and vagina.

Amino Acid Sequence↗
PubMed1994

Distribution of neuropeptide Y-like immunoreactivity in the hypothalamic tuberal nuclei of the immature gilts.

The distribution of neuropeptide Y in the immature female pig hypothalamic tuberal nuclei was investigated using avidin-biotin complex method. This study showed cell bodies containing NPY-immunoreactive material in the arcuate nucleus, dorsomedial and ventromedial nuclei, as well as internal layer of the median eminence and infundibulum, an observation not yet reported in the pig. NPY-immunoreactive fibers were noted throughout the hypothalamus, but most prominently within the periventricular region. Median eminence disclosed abundance of NPY-immunoreactive processes. The study shows a detailed organization of cell bodies and fibers containing NPY-immunoreactivity in tuberal hypothalamic nuclei of the immature gilts.

Animals↗
PubMed1993

Immunocytochemical demonstration of neuropeptide Y and luteinizing hormone-releasing hormone-immunoreactive structures in the organum vasculosum laminae terminalis of juvenile gilts.

Immunocytochemical investigations on the immature gilt organum vasculosum laminae terminalis showed extensive neuropeptide Y- and luteinizing hormone-releasing hormone-immunoreactive innervation of the organ. The luteinizing hormone-releasing hormone-containing varicose fibers ran along the organum vasculosum laminae terminalis in close association with blood vessels. The nerve processes originating from well-stained luteinizing hormone-releasing hormone-immunoreactive perikarya were distributed around the organum vasculosum laminae terminalis. The matrix of the organum vasculosum laminae terminalis was abundantly supplied by neuropeptide Y-immunoreactive varicose fibers. Numerous neuropeptide Y-immunoreactive terminals seemed to penetrate the ependymal lining of the organ. From these observations, it is concluded that there are favorable morphological conditions for secretion of neuropeptide Y into the cerebrospinal fluid of the third ventricle and release of luteinizing hormone-releasing hormone into fenestrated capillaries of the organ.

Animals↗
PubMed1993

Distribution of neuropeptides in the porcine stellate ganglion.

The localization and distribution of neuropeptides including neuropeptide Y (NPY), [Met5]enkephalin-Arg6-Gly7-Leu8 (MEAGL), vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), substance P and somatostatin (SOM) were analyzed in the stellate ganglion of the pig by use of the indirect immunofluorescence technique. NPY, MEAGL, SOM, VIP and CGRP immunoreactivities were found to exist in subpopulations of neuronal cell bodies of the stellate ganglion. A population of the small intensely fluorescent (SIF) cells showed MEAGL immunoreactivity. In addition, the presence of NPY-, MEAGL-, CGRP-, SP-, SOM- and VIP-immunoreactive nerve fibers and axonal varicosities were observed in the stellate ganglion. The localization and pattern of distribution of these peptides in the porcine stellate ganglion were compared with studies carried out on stellate ganglia of other mammalian species.

Animals↗
PubMed1993

Neuropeptides in the porcine coeliac-superior mesenteric ganglion.

The occurrence and distribution of tyrosine hydroxylase, neuropeptide Y, somatostatin, Met5-enkephalin-Arg6-Gly7-Leu8, vasoactive intestinal polypeptide, substance P, calcitonin gene-related peptide, bombesin gastrin releasing peptide and galanin were immunohistochemically studied in the perikarya and nerve fibres of the porcine coeliac-superior mesenteric ganglion of untreated juvenile pigs. Subpopulations of neurons containing immunoreactivities to tyrosine hydroxylase, neuropeptide Y, Met5-enkephalin-Arg6-Gly7-Leu8, somatostatin, vasoactive intestinal polypeptide and galanin were disclosed in the studied ganglion, whereas principal ganglionic cells were non-immunoreactive for other investigated peptides. Double-immunofluorescence and analysis of consecutive sections revealed a partial colocalization of tyrosine hydroxylase and neuropeptide Y, Met5-enkephalin-Arg6-Gly7-Leu8 and somatostatin, whereas immunoreactivity to vasoactive intestinal polypeptide and/or to neuropeptide Y was found in non-noradrenergic neurons in this ganglion. All of neuropeptides studied were found in nerve fibres in this ganglion. The results of this study were compared with those of previous studies performed on other species.

Amino Acid Sequence↗
PubMed1993

Adrenergic and acetylcholinesterase-positive innervation of the bovine oviduct.

Adrenergic and cholinesterase-positive (AChE-positive) innervation of the bovine oviduct was studied using histochemical methods. Both subpopulations of the studied nerve fibres were found in the isthmus, ampulla and infundibulum where they were mainly related to the muscular coat or blood vessels of the organ. The adrenergic innervation was found to be much better developed than the cholinergic one. Adrenergic and cholinergic nerves were numerous in the isthmal port of the Fallopian tube, whereas these fibres were less numerous in the ampulla. The infundibulum contained the smallest number of adrenergic and ACHE-positive nerve fibres.

Acetylcholinesterase↗
PubMed1993

Adrenergic innervation of the epididymis, vas deferens, accessory genital glands and urethra in the boar.

The distribution of adrenergic nerve fibres in the urethra and some organs of the male reproductive system of juvenile boars was studied by applying the glioxylic acid-induced fluorescence method. Adrenergic nerve fibres were found in all structures examined, with particular relation to their muscular coats and arterial blood vessels. Ductuli efferentes and ductus epididymidis from the caput region were weakly innervated. The number of adrenergic nerve fibres innervating the ductus epididymidis gradually increased towards the cauda epididymidis, being greatest in this region. The vas deferens was very well supplied with these nerves. The seminal vesicle was found to be the richest innervated organ in comparison with other accessory genital glands. The body of the prostate was slightly weaker innervated, while the disseminated part of the prostate as well as the bulbourethral gland comprised the smallest number of adrenergic nerve fibres. The urethra received a very dense adrenergic nerve supply. The pelvic part of the urogenital duct possessed a moderate number of adrenergic nerves, which supplied not only the muscular membrane but also venous sinuses of the mucosa. In a close vicinity to the internal genital organs numerous ganglia containing both adrenergic and non-adrenergic nerve cell bodies were observed. The presented data suggest that adrenergic innervation may be deeply involved in the control of blood flow and motor function of the organs studied, and that a part of adrenergic nerve fibers innervating these structures may originate from pelvic ganglia.

Adrenergic Fibers↗
PubMed1992

Immunohistochemical localization of calcitonin gene-related peptide and cotransmitters in a subpopulation of post-ganglionic neurons in the porcine inferior mesenteric ganglion.

Applying double-fluorescence immunohistochemistry, adrenergic and non-adrenergic postganglionic sympathetic neurons, in the porcine inferior mesenteric ganglion (IMG) are subdivided according to size and cotransmitter content. Calcitonin gene related peptide (CGRP)-immunoreactive (IR) neurons are demonstrated to belong to the non-adrenergic, i.e. tyrosine hydroxylase- and DOPAmine-beta-hydroxylase-(D beta H)-negative subpopulation of postganglionic perikarya. Virtually all of the CGRP-IR postganglionic neurons exhibit colocalization with somatostatin (SOM), and, some of them with neuropeptide tyrosine (NPY). Additionally, NPY-, SOM-, and NPY/SOM-IR subpopulations of adrenergic and non-adrenergic neurons are observed. CGRP-immunoreactivity is seen in dense networks of intraganglionic varicose nerve fibres, adjacent to the TH- and SOM-IR neurons. NPY-IR perikarya are sparsely supplied by CGRP-IR fibres. SOM- and NPY-IR nerve fibres also exist in the inferior mesenteric ganglion. The functional relevance of CGRP-IR postganglionic neurons, as well as target organs of these neurons remain to be elucidated.

Animals↗
PubMed1992

Effects of a new pteridine derivative on urinary sodium, potassium and magnesium excretion in conscious saline-loaded rats.

1. Two recently synthesized pteridine derivatives (RPH 3036; RPH 3038) were tested in conscious saline-loaded rats and showed natriuretic and antimagnesiuretic properties but hardly reduced potassium excretion. 2. In the same model a dose-response curve was performed for RPH 3036. ED50 and Emax values were calculated for the natriuretic (ED50 = 13.4 mumol kg-1; Emax = 1.08 mmol kg-1) and antimagnesiuretic (ED50 = 11.3 mumol kg-1; Emax = -0.099 mmol kg-1) properties of RPH 3036. There were no significant changes of potassium and calcium excretion. 3. After a single dose of RPH 3036 (100 mumol kg-1) the time course of electrolyte excretion was analysed over 6 h. RPH 3036 did not show any significant effects on renal potassium and calcium excretion whereas a pronounced decrease (P less than 0.01) in renal magnesium excretion was evident during the 6 h. A moderate increase of sodium excretion was observed only after 3, 5 and 6 h. 4. A selective reduction of magnesium secretion in the late distal tubule and collecting duct was proposed as a possible mechanism of action of RPH 3036. This would explain the fast onset of action as well as the lack of antikaliuretic and anticalciuretic effects. The high selectivity of RPH 3036 makes it potentially valuable for the future investigation of renal magnesium transport.

Animals↗
PubMed1992

Synthesis, natriuretic, antikaliuretic and antimagnesiuretic properties of an acidic triamterene derivative.

2,4,7-Triamino-6-(4-methanesulfonamidophenyl) pteridine (RPH 3048) is a new acidic triamterene derivative. Relevant physico-chemical constants were determined (solubility at pH 7.4 = 3.7 mg/l; logP at pH 7.4 = 0.2) and pharmacokinetic as well as pharmacodynamic properties were investigated, using male Wistar rats. After intravenous application of the test substances urine was collected, its volume and electrolyte composition determined, and the urine recovery of the drugs was analysed. The comparison of RPH 3048 with triamterene (CAS 396-01-0) revealed almost equipotent natriuretic and potassium-retaining effects for both drugs and an additional relative magnesium-sparing activity of RPH 3048. The urine recovery of RPH 3048 after 6 h was higher (20.6%) than that of triamterene (12.9%). No metabolite of RPH 3048 could be detected in the urine whereas a triamterene metabolite was found. Due to its good solubility in alkaline medium RPH 3048 could be dissolved (at pH 11-12) and then administered intravenously together with a loop diuretic (furosemide). Urinary electrolyte excretion following administration of two different combinations of RPH 3048 and furosemide (combination A: 12.5 mumol/kg RPH 3048 and 25 mumol/kg furosemide; combination B: 25 mumol/kg RPH 3048 and 25 mumol/kg furosemide) was compared to urinary electrolyte excretion of a control group and a group only treated with furosemide (25 mumol/kg). The additional application of RPH 3048 reduced in both groups potassium and magnesium excretion to control level but did not compromise furosemide induced natriuresis. In contrast to earlier investigations these results suggest that it is possible to develop acidic triamterene derivatives with potent antikaliuretic effects.

Animals↗
PubMed1991

Distribution of somatostatin- and neuropeptide Y-immunoreactive nerve fibers in the porcine female reproductive system.

The localization and distribution of somatostatin and neuropeptide Y were studied in the porcine female reproductive system with the indirect immunofluorescence technique. Somatostatin-immunoreactive nerve fibers were observed in different parts of the ovary and in the muscular membrane of the uterus as well as in the mesosalphinx. Somatostatin-immunoreactive neurons were detected in the inferior mesenteric ganglion. Neuropeptide Y immunoreactivity was present in a large number of nerve fibers distributed in different regions of the uterus, oviduct and ovary. The present results suggest that the porcine female genital organs receive innervation by somatostatin- and neuropeptide Y-containing nerve fibers, but their exact functional role remains to be established.

Animals↗
PubMed1991

The origin of ovarian neuropeptide Y (NPY)-immunoreactive nerve fibres from the inferior mesenteric ganglion in the pig.

Applying a double-immunofluorescence technique, the porcine ovary is demonstrated to receive two populations of NPY-immunoreactive nerve fibres originating from the inferior mesenteric ganglion: one with colocalized tyrosine hydroxylase and supplying predominantly the ovarian vasculature, and a second, solely NPY-immunoreactive and almost exclusively associated with growing follicles. A third group of tyrosine hydroxylase- and dopamine-beta-hydroxylase-positive, but NPY-negative nerve fibres is associated with ovarian blood vessels and, to a minor extent, with ovarian follicles. As revealed by retrograde tracing, the vast majority of postganglionic neurons projecting to the ovary is located in a discrete area of the ganglion, suggesting a somatotopic organization of the porcine inferior mesenteric ganglion. Moreover, the findings indicate that three subpopulations of postganglionic sympathetic neurons with different chemical codes supply different target components of the porcine ovary. The physiological relevance of the described neurons in the nervous control of ovarian functions remains to be elucidated.

Animals↗
PubMed1990

Adrenergic innervation of the lower urinary tract in cattle.

Studies were carried out on 8 sexually immature male calves. Sections of the ureters, urinary bladder, and urethra were cut with a freezing microtome and the method of Kyösöla et al. (1980) was used to visualize the adrenergic nerve fibres. It was found that bovine ureters possessed weak innervation; most of the nerves was located in the muscular membrane, and only in the paravesical part, sparse nerve fibres were found in the submucosa of this one. Apex of the urinary bladder was more weakly supplied with the adrenergic nerves than the corpus, whereas bladder's trigonum and cervix possessed numerous nerve fibres in both muscular and submucosal membranes. The distribution pattern of adrenergic nerves in the urethra was similar to that of urinary bladder's cervix. The presence of adregeneric nerve fibres was found in submucosal layer of both the urinary bladder and the urethra. Part of the nerves was connected with blood vessels of the organs under study.

Adrenergic Fibers↗