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Biomedical subjects

B Ottesen

Publications and source records attributed to B Ottesen.

At least 55 records · Page 3Linked to original sources
PubMed1994

Pituitary adenylate cyclase activating polypeptide induces vascular relaxation and inhibits non-vascular smooth muscle activity in the rabbit female genital tract.

In vitro effects of two bioactive forms of pituitary adenylate cyclase activating polypeptide (PACAP): PACAP-38 and PACAP-27 were studied on rabbit vascular and non-vascular smooth muscle. Segments of the ovarian artery and muscle strips from the fallopian tube were used. Two series of experiments were performed on vessels: the dose-response relationship of PACAP-38 (10(-10)-10(-7) M) was established on noradrenaline- (NA, 10(-6) M) contracted vessels. In the other set of experiments the contractile effect of 10(-8)-10(-4) M NA added cumulatively, was studied on arterial segments incubated with PACAP-38 (10(-7) M), PACAP-27 (10(-7) M) or VIP (10(-7) M). The effect of PACAP-38, PACAP-27 and VIP (10(-10)-10(-6) M) was investigated on spontaneously contracting smooth muscle of the fallopian tube. Longitudinally as well as transversally cut specimens were investigated. PACAP-38 produced a significant dose-related relaxation on the NA-precontracted vessels. However, pre-incubation of the vessels with 10(-7) M PACAP-38, PACAP-27 and vaso active intestinal polypeptide (VIP) did not induce a general rightward shift of the NA concentration-response curves, although a tendency to inhibition in the low-dose interval was observed. The peptides caused a significant, dose-dependent inhibition of both frequency and amplitude on the fallopian tube smooth muscle activity. The effects of the three peptides on longitudinally as well as transversally cut specimens were alike.

Animals↗
PubMed1993

Expression of epidermal growth factor receptors in human endometrial carcinoma.

Little data exist on the expression of epidermal growth factor receptors (EGF-Rs) in human endometrial cancer. EGF-R status was studied in 65 patients with endometrial carcinomas and in 26 women with nonmalignant postmenopausal endometria, either inactive/atrophic endometrium or adenomatous hyperplasia. EGF-R was identified on frozen tissue sections by means of an indirect immunoperoxidase technique with a monoclonal antibody against the external domain of the EGF-R. Seventy-one percent of the carcinomas expressed positive EGF-R immunoreactivity. In general, staining was most prominent at the cell membranes, with a varying pattern in individual carcinomas. EGF-R expression was not correlated with histologic grade, surgical stage, or estrogen/progesterone receptor status evaluated immunohistochemically or biochemically in adjacent tissue sections of the tumor. Ten of 13 (77%) atrophic/inactive endometria and seven of 13 (54%) endometria with adenomatous hyperplasia were EGF-R positive, with an immunostaining pattern rather similar to that of the carcinomas.

Aged↗
PubMed1992

Peptide histidine valine (PHV) is present and biologically active in the human female genital tract.

The occurrence of vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM) and peptide histidine valine (PHV) in the human female genital tract was studied by means of radioimmunoassay in combination with gel chromatography. In addition, the effect of PHV on genital smooth muscle activity was investigated in vitro and compared to that of VIP. Immunoreactive VIP, PHM and PHV were present in all regions of the human female genital tract, the highest concentrations being measured in the vagina and the uterine cervix. The peptides displayed similar regional distribution and as expected from the structure of the VIP precursor molecule in which the examined peptides are contained, the molar ratio of VIP to the total PHM/PHV immunoreactivity was close to 1:1. In all regions PHV constituted 50-70% of the total PHM/PHV immunoreactivity indicating that the dibasic conversion site after PHM was uncleaved. VIP and PHV were found to be equipotent relaxants of the smooth muscle from the Fallopian tube and the myometrium. The present study indicates that PHV like PHM and VIP may act as a neurotransmitter in the human female genital tract and thus participate in the local nervous control of the reproductive functions.

Adult↗
PubMed1992

Intracavernous self-injection with vasoactive intestinal polypeptide and phentolamine in the management of erectile failure.

A total of 52 men, median age 55 years (range 28 to 74 years), with erectile failure was treated with vasoactive intestinal polypeptide and phentolamine. Impotence was classified as psychogenic in 3 patients, psychogenic/arteriogenic in 3, arteriogenic in 25, arteriogenic/neurogenic in 4, neurogenic in 5, venous leakage/psychogenic in 2, venous leakage/neurogenic in 1 and following venous leak surgery in 9. The patients were treated with 30 micrograms vasoactive intestinal polypeptide and 0.5 to 2.0 mg. phentolamine. A total of 1,380 self-injections was given and the number of injections per patient varied from 5 to 245. No patient had priapism, corporeal fibrosis or other serious complications. After sexual stimulation all patients obtained erection sufficient for penetration. Following ejaculation rigidity decreased normally. The median duration of treatment was 6 months (range 1 to 22). Nine patients discontinued treatment. One patient with severe arteriosclerosis experienced decreased effectiveness of the drug and received a penile prosthesis. Five patients elected not to perform self-injection any longer, 1 psychogenic impotent patient was cured, and 1 patient discontinued therapy due to palpitation and sweating. One patient died of a myocardial infarction not associated with this therapy.

Adult↗
PubMed1992

Vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM) in human penile corpus cavernosum tissue and circumflex veins: localization and in vitro effects.

Localization and functional effects of vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM), two peptides derived from a common precursor molecule, were investigated in isolated preparations from human penile corpus cavernosum (CC) and circumflex vein (CV). VIP- and PHM-immunoreactivity (IR) was demonstrated in both CC and CV. The concentrations of VIP-IR and PHM-IR in CC tissue were 54.4 +/- 15.3, and 42.0 +/- 7.5 pmol g-1 wet weight respectively with a VIP/PHM ratio of 1.5 +/- 0.4 (mean +/- SEM). The corresponding values for CV tissues were 28.0 +/- 7.7 and 9.6 +/- 2.6 pmol g-1 wet weight with a VIP/PHM ratio of 3.1 +/- 0.4. CC and CV displayed VIP- and PHM-IR confined to nerve fibres in close relation to bundles of smooth muscle cells and blood vessels in both tissues. In vitro, VIP and PHM had no effects in unstimulated tissue preparations. Both peptides concentration-dependently (10(-9)-10(-6) M) relaxed CC and CV preparations precontracted with 3 x 10(-6) M noradrenaline. In CC the maximum relaxant effect of VIP and PHM was 22 +/- 11% and 9 +/- 9% and in CV the corresponding values were 82 +/- 8% and 93 +/- 3% respectively. The present study supports the hypothesis of VIP and PHM as neurotransmitters and/or neuromodulators in the nervous control of penile erection.

Adolescent↗
PubMed1991

Vasoactive intestinal polypeptide loses its ability to increase vaginal blood flow after menopause.

The effect of vasoactive intestinal polypeptide on vaginal blood flow was investigated in postmenopausal women. In women who were receiving hormonal replacement therapy the vasodilatory response induced by vasoactive intestinal polypeptide was identical to that of young women, whereas in postmenopausal women who were receiving no replacement therapy, the response induced by vasoactive intestinal polypeptide was absent. Plasma levels of vasoactive intestinal polypeptide and systemic cardiovascular effects were identical in the two groups.

Blood Pressure↗
PubMed1991

Neuropeptide Y (NPY) in human penile corpus cavernosum tissue and circumflex veins--occurrence and in vitro effects.

The concentration and distribution of neuropeptide Y (NPY) within the penile corpus cavernosum (CC) and in penile circumflex veins (CV) from healthy potent males was investigated by immunochemistry and immunohistochemistry. The concentrations were assessed to 28.6 pmol/gm. (CC) and 15.8 pmol/gm. (CV) respectively. Gel filtration on CC tissue extracts demonstrated a single peak of NPY-immunoreactivity (NPY-IR) similar to synthetic human NPY. The NPY-IR was confined to nerve fibers seemingly innervating smooth muscle cells. In vitro myographic examinations demonstrated contractile activation by NPY in 2/8 CC strips and in 5/8 CV strips. The mean contractile force was 1.17 +/- 0.62 mN (18.3 +/- 15.8% of the K(+)-induced contraction) and 2.42 +/- 0.42 mN (31 +/- 12%) respectively. NPY 10(-7) and 10(-6) M displayed a potentiating effect on the response to NA 10(-9) in one of six CC and four of six CV preparations. It is suggested that NPY could add to the contractile effect of NA in detumescence and in maintenance of the resting state; contribution of NPY to the veno-occlusive mechanism at initiation of erection is another putative physiological function.

Adult↗
PubMed1991

Effect of regulatory peptides on the blood flow rate in rabbit female genital tract evaluated by the 133Xe technique.

The 133Xe washout method has been evaluated and found to be a reliable method for the measurement of myometrial as well as ovarian blood flow rates in the rabbit. Monoexponential washout curves for 133Xe have been demonstrated for the whole washout process, both in the uterus and the ovary. Consequently it is possible to calculate the blood flow rate at any time interval during the whole washout process. This 133Xe washout technique has been used for the evaluation of the biological effect of neuropeptides on the local blood flow within the rabbit uterus and ovary. It has been recognized for years that the intrinsic control of a number of functions, including the blood flow regulation, in the genital tract cannot be attributed to cholinergic and/or adrenergic nerves alone. Evidence from 133Xe experiments suggests that the neuropeptides in the female genital tract may play a functional role in these non cholinergic non adrenergic events.

Animals↗
PubMed1990

Opioid-like immunoreactants in human cervical cancer.

Cervical carcinoma cell lines produce several polypeptide hormones. While screening human cervical cancers for such factors we have found many tumors to be immunoreactive for opioid peptides. The tumors were collected at surgery or prior to actinotherapy, fixed in buffered formalin, paraffin-embedded, and immunocytochemically stained using the PAP method. The localization of opioid-like immunoreactivity was investigated using a primary antiserum recognizing the Tyr-Gly-Gly-Phe sequence common to all known opioid peptides. The presence of neuropeptide Y (NPY) and peptide histidine methionine (PHM), both known to be present in normal human cervical tissue, was also investigated using specific antisera. Controls included staining controls and absorption controls, using Sepharose-coupled antigen and were all negative. Out of 40 cervical carcinomas, 27 displayed varying numbers of opioid-immunoreactive cells. In 12 normal cervical specimens no specific staining was observed. None of the tumors displayed any NPY-like or PHM-like immunoreactivity. The growth of cervical carcinoma seems therefore to be accompanied by a destruction of the local peptidergic innervation of blood vessels and smooth muscle cells. The demonstration of opioid-like immunoreactants and the known immunoregulatory properties of these peptides, indicate that opioid peptides may be important in the regulation of growth of human cervical carcinoma.

Adult↗
PubMed1990

Vasoactive intestinal polypeptide and human vaginal blood flow: comparison between transvaginal and intravenous administration.

1. The present study was performed to examine and compare the effect of increasing doses of vasoactive intestinal polypeptide (VIP) on vaginal blood flow following vaginal subepithelial and intravenous injection in normal women. 2. Local vaginal blood flow was measured by a heated oxygen electrode. 3. Peripheral blood samples were collected throughout the experiments for VIP analysis by radioimmunoassay. 4. Both subepithelial and intravenous injections induced a significant and dose-dependent increase in vaginal blood flow (P less than 0.05), displaying the same efficacy, potency and sensitivity. 5. The vaginal flow values correlated with the corresponding plasma VIP concentrations after both routes of administration. 6. The systemic vascular side effects; that is, flushing, hypotension and tachycardia, were observed following both subepithelial and intravenous injection. 7. The findings indicate that the effect of VIP on vaginal blood flow irrespective of route of administration is part of a systemic vasodilatory effect rather than a local response.

Adult↗
PubMed1990

Vasoactive intestinal polypeptide in the PMSG-primed immature rat ovary and its effect on ovulation in the isolated rat ovary perfused in vitro.

The immature rat ovary contains VIP immunoreactive nerve fibres sparsely distributed around blood vessels, in the interstitial gland and around follicles. The VIP concentration, measured radioimmunologically, decreased significantly after PMSG treatment (10 i.u.), probably due to ovarian enlargement and oedema, while the total VIP content (total of 0.12 pmol in both ovaries) did not change after PMSG priming. The ovulatory effect of VIP was studied using in-vitro perfused ovaries from immature 28-day-old rats primed with 10 i.u. PMSG. In all ovaries perfused, VIP (10(-7) M) induced ovulations with a rate of 2.33 +/- 0.56. The ovulation rate was significantly lower than that of ovaries stimulated by LH (0.1 microgram/ml) (5.20 +/- 0.86 ovulations per ovary). No synergistic effect on the ovulation rate was seen when LH and VIP were administered together (5.20 +/- 0.49 ovulations per ovary). The results suggest that the neuropeptide VIP may represent one of the local factors involved in the ovulation process.

Animals↗
PubMed1989

Regulatory peptides in the mammalian urogenital system.

By immunocytochemistry a number of the gut/brain peptides have been demonstrated in nerve fibers of the mammalian urogenital tract. These peptides are localized to large vesicles in nerve terminals of afferent fibers or efferent nerves innervating blood vessels, non-vascular smooth muscle, lining epithelium and glands. There is evidence that some neuropeptides (VIP, NPY) participate in the local non-cholinergic, non-adrenergic nervous control of smooth muscle activity and blood flow, while other peptides (substance P, CGRP) seem to be sensory transmitters. It is likely that impaired function of the peptidergic nerves is involved in sexual dysfunction such as male impotence.

Animals↗
PubMed1989

Non-amidated forms of VIP (glycine-extended VIP and VIP-free acid) have full bioactivity on smooth muscle.

The aim of the present study was to elucidate the importance of the C-terminal amide group for the biological activity of vasoactive intestinal peptide (VIP). Two synthetic peptides lacking the amide group: VIP having a carboxyl group at the C-terminus and the intermediate biosynthetic precursor, glycine-extended VIP were compared with VIP itself regarding the ability to inhibit spontaneous activity in smooth muscle strips from rat stomach and human Fallopian tube. Both the glycine-extended VIP and VIP having a carboxyl group at the C-terminus caused a significant and dose-dependent inhibition of smooth muscle activity and displayed dose-response curves similar to VIP. The potencies of the VIP variants did not differ significantly from that of VIP. Thus, alpha-carboxyamidation of VIP is not a prerequisite for biological activity.

Animals↗
PubMed1989

Peptide histidine methionine and vasoactive intestinal peptide: occurrence and relaxant effect in the human female reproductive tract.

The occurrence of the neuropeptides peptide histidine methionine (PHM) and vasoactive intestinal peptide (VIP) in the human female genital tract was studied by means of immunochemistry and radioimmunoassay in combination with gel chromatography. In addition, the effect of PHM and VIP on smooth muscle activity was investigated in vitro. The regional distribution of PHM as determined by radioimmunoassay correlated with that of VIP. This finding agreed with the immunohistochemical data, which, in addition, provided evidence for colocalization of the two peptides in nerve fibers. These fibers were most abundant in the vagina and the uterine cervix, where they seemed to innervate blood vessels, smooth muscle, and epithelial cells. The concentrations of immunoreactive PHM and VIP were found to be similar in all areas except in the vagina, where the PHM concentration was fourfold that of VIP. Gel chromatography of vaginal extract revealed a high concentration of a C-terminally extended form of PHM, suggesting differential processing pathways of the VIP precursor. Both PHM and VIP inhibited, in a dose-dependent manner, the smooth muscle activity in strips from the Fallopian tube and the myometrium. Administered in combination, PHM and VIP had an additive effect and displayed the same efficacy as VIP alone, indicating that the peptides act via a common receptor.

Adult↗
PubMed1989

Neuropeptide Y in the human female genital tract: localization and biological action.

The distribution, localization, and smooth muscle effects of neuropeptide Y (NPY) were studied in the human female genital tract. High concentrations of NPY immunoreactivity were demonstrated in the uterine artery, the ovary, the fallopian tube, cervix, and the vagina. The NPY immunoreactivity was confined to nerve fibers. The highest density of nerve fibers was observed in relation to blood vessels, although some NPY-immunoreactive nerves were also seen close to nonvascular smooth muscle. The NPY-immunoreactive material throughout the genital tract was identical to synthetic amidated human NPY with regard to size, hydrophobicity, and charge as evaluated by gel filtration, high-performance liquid chromatography, and isoelectric focusing. NPY (10(-10) to 10(-6) M) exerted a direct vasoconstrictory effect on small arteries dissected from the cervix and an additive effect of NPY and norepinephrine responses was observed. Exogenous NPY did not have a direct effect on nonvascular smooth muscle specimens from the fallopian tube or the myometrium. The close relation between NPY-immunoreactive nerves and blood vessels, the presence of NPY-immunoreactive material identical to amidated synthetic human NPY, and the vasoconstrictory effects of NPY indicate that NPY is involved in the regulation of the blood flow in the human female genital tract.

Antibodies↗
PubMed1988

Release of oxytocin and vasopressin by intracerebroventricular vasoactive intestinal polypeptide.

Vasoactive intestinal polypeptide (VIP)ergic nerves innervate both the neurohypophysis and the hypothalamus. To test the hypothesis that VIP is a releasing factor for neurohypophyseal hormones, rats were given intracerebroventricular (icv) infusions of VIP in doses varying from 0.3 pmol/kg.min to 3 nmol/kg.min for 5 min (0.001-10 micrograms/rat). Serial blood samples were drawn from the vena cava for measurement of oxytocin (OT), vasopressin (AVP), and VIP by RIA. After the VIP infusions mean plasma OT and AVP levels rose in a dose-dependent manner; the rise was significant for both hormones at the dose of 300 pmol/kg.min. Peak levels after infusion of 3 nmol/kg.min were greater for OT than AVP [96.1 +/- 14.7 vs. 33.9 +/- 9 microU/ml (mean +/- SE); n = 6]. In addition, the concentration of plasma OT increased more promptly than that of AVP. Plasma OT was significantly raised over control values at 5 min, whereas plasma AVP was not increased until 15 min after the VIP infusion began. The concentration of VIP in peripheral plasma rose somewhat after icv infusions (maximum, 300 pmol/liter 30 min after 10 micrograms/rat), but the rise was only 5% of that observed after systemic infusions of equimolar doses of VIP (maximum, 6000 pmol/liter 5 min after 10 micrograms/rat). Peak plasma OT levels after administration of 3 nmol/kg.min VIP were significantly higher after icv than after systemic infusion of the same dose of VIP reported previously. Intravenous injection of 0.5 ml VIP antiserum with a binding capacity of VIP of 2.3 micrograms/ml before the icv administration of VIP (1 microgram/rat) did not prevent the VIP-induced rise in plasma OT and AVP. These observations suggest a central site of action for VIP in OT and AVP release, probably in the hypothalamus. The results are in harmony with the hypothesis that endogenous VIP is a physiological regulator of OT and AVP release in rats.

Animals↗
PubMed1988

Effects of VIP and PHM in human intracervical arteries.

The relaxing effects of vasoactive intestinal polypeptide (VIP) and peptide histidine methionine (PHM) on human intracervical arteries were studied. Cervical tissue specimens were excised after hysterectomy at various phases of the menstrual cycle (n = 12) and small intracervical arteries were dissected free by microtechnique. Ring preparations of the vessels were prepared and mounted in organ baths, and isometric circular tension was recorded. None of the compounds showed any effects in unstimulated cervical arterial preparations. In vessels precontracted by noradrenalin 10(-5) M, VIP 10(-8) - 10(-6) M and PHM 10(-8) - 10(-6) M induced similar, concentration-dependent relaxation with a maximum effect of 73.2 +/- 12.7% relaxation for VIP 10(-6) M and 79.6 +/- 11.8% for PHM 10(-6) M, as compared to 10.7 +/- 3.1% decrease in tension for control preparations treated with solvent (mean +/- SE, n = 6). Simultaneous addition of VIP 5 x 10(-7) M and PHM 5 x 10(-7) M produced additive effects. Pretreatment with indometacin 10(-6) M, atropine 10(-6) M or propranolol 10(-6) M did not significantly influence these responses. Both peptides might be involved in regulation of blood flow in the human cervix.

Cervix Uteri↗