Cholinergic activation of brain stem neurons increases intravesical pressure mediated by vasopressin release in female rats

ABSTRACT Drugs able to mimic or to antagonize the action of catecholamines have been implanted bilaterally into the basomedial region of the amygdala of adult castrated female rats. The animals were killed at different intervals after the implantation of the different drugs, and serum levels of LH and FSH were measured by radioimmunoassay. The results have shown that the intra-amygdalar implantation of the alpha-adrenergic blocker phenoxybenzamine induces a significant increase of the release both of LH and FSH. The implantation of the beta-adrenergic blocker propranolol brings about a rise of LH only. The dopamine receptor blocker pimozide stimulates the release of LH and exerts a biphasic effect (stimulation followed by inhibition) of FSH secretion. The alpha-receptor stimulant clonidine and the dopaminergic drug 2-Br-alpha-ergocryptine were without significant effects. From these observations it is suggested that the adrenergic signals reaching the basomedial area of the amygdala (possibly from the brain stem) may be involved in the modulation of gonadotrophin secretion.

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Increased plasma osmolality stimulates peripheral and central vasopressin release in male and female rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1994.267.4.r923 ◽

1994 ◽

Vol 267 (4) ◽

pp. R923-R928 ◽

Cited By ~ 3

Author(s):

M. Ota ◽

J. T. Crofton ◽

H. Liu ◽

G. Festavan ◽

L. Share

Keyword(s):

Interstitial Fluid ◽

Plasma Osmolality ◽

Female Rats ◽

Microdialysis Probe ◽

Vasopressin Release ◽

Arterial Blood ◽

Plasma Vasopressin ◽

Male And Female Rats ◽

Supraoptic Nuclei

It has been demonstrated that the neurohypophysial hormones can be released intrahypothalamically by the paraventricular (PVN) and supraoptic nuclei. The present experiments were undertaken to determine whether a physiological stimulus for vasopressin release, increased plasma osmolality, will stimulate the release of vasopressin by the PVN into the surrounding interstitial fluid, and whether the responses are affected by gender. Intravenous infusion of 2.5 M NaCl for 60 min (0.1 ml.kg-1.min-1) in conscious rats resulted in an increased vasopressin concentration in the dialysate from a microdialysis probe adjacent to the PVN. This response was greater in nonestrous females than in males. On the other hand, the rise in the plasma vasopressin concentration was greater in males than in nonestrous females. Mean arterial blood pressure increased and heart rate decreased, but these responses were not affected by gender. The role of centrally released vasopressin in the control of the peripheral release of vasopressin is conjectural, but both responses may be modulated by the gonadal steroid hormones.

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Strain differences in pH-sensitive K+ channel-expressing cells in chemosensory and nonchemosensory brain stem nuclei

Journal of Applied Physiology ◽

10.1152/japplphysiol.00439.2014 ◽

2014 ◽

Vol 117 (8) ◽

pp. 848-856 ◽

Cited By ~ 3

Author(s):

Paul F. Martino ◽

S. Olesiak ◽

D. Batuuka ◽

D. Riley ◽

S. Neumueller ◽

...

Keyword(s):

Brain Stem ◽

Nucleus Tractus Solitarius ◽

Ph Sensitive ◽

Nucleus Ambiguus ◽

Female Rats ◽

Brown Norway ◽

Motor Nucleus ◽

Male And Female ◽

Male And Female Rats ◽

Bötzinger Complex

The ventilatory CO2 chemoreflex is inherently low in inbred Brown Norway (BN) rats compared with other strains, including inbred Dahl salt-sensitive (SS) rats. Since the brain stem expression of various pH-sensitive ion channels may be determinants of the CO2 chemoreflex, we tested the hypothesis that there would be fewer pH-sensitive K+ channel-expressing cells in BN relative to SS rats within brain stem sites associated with respiratory chemoreception, such as the nucleus tractus solitarius (NTS), but not within the pre-Bötzinger complex region, nucleus ambiguus or the hypoglossal motor nucleus. Medullary sections (25 μm) from adult male and female BN and SS rats were stained with primary antibodies targeting TASK-1, Kv1.4, or Kir2.3 K+ channels, and the total (Nissl-stained) and K+ channel immunoreactive (-ir) cells counted. For both male and female rats, the numbers of K+ channel-ir cells within the NTS were reduced in the BN compared with SS rats ( P < 0.05), despite equal numbers of total NTS cells. In contrast, we found few differences in the numbers of K+ channel-ir cells among the strains within the nucleus ambiguus, hypoglossal motor nucleus, or pre-Bötzinger complex regions in both male and female rats. However, there were no predicted functional mutations in each of the K+ channels studied comparing genomic sequences among these strains. Thus we conclude that the relatively selective reductions in pH-sensitive K+ channel-expressing cells in the NTS of male and female BN rats may contribute to their severely blunted ventilatory CO2 chemoreflex.

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Sex differences in central adrenergic control of vasopressin release

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1989.257.5.r1040 ◽

1989 ◽

Vol 257 (5) ◽

pp. R1040-R1045 ◽

Cited By ~ 1

Author(s):

J. D. Stone ◽

J. T. Crofton ◽

L. Share

Keyword(s):

Female Rats ◽

Male Rats ◽

Gonadal Steroid Hormones ◽

Gonadal Steroid ◽

Vasopressin Release ◽

Arterial Blood ◽

Adrenergic Control ◽

Vasopressin Secretion ◽

Males And Females ◽

Plasma Arginine

Central adrenoreceptor-mediated regulation of vasopressin secretion and cardiovascular function was studied in male rats and female rats in specific estrous cycle phases. In conscious, unrestrained rats with intracerebroventricular (icv) cannulas and femoral artery and vein catheters, plasma arginine vasopressin concentration (PAVP), mean arterial blood pressure (MABP), and heart rate (HR) were determined before and 5 and 15 min after icv injection of 10 micrograms norepinephrine or 50 micrograms phenylephrine. Norepinephrine (icv) increased PAVP in proestrus and metestrus four and three times (P less than 0.01 and 0.05, respectively) more than in males. Norepinephrine induced similar MABP elevations (P less than 0.01) in males and females in all cycle phases; HR decreased only in proestrus, estrus, and metestrus (P less than 0.01). The increase in PAVP after icv phenylephrine was four and three times greater in proestrous and diestrous females (P less than 0.01 and 0.05, respectively) than in males. The proestrous MABP rise was three times that in males (P less than 0.05); HR decreased similarly in diestrus, proestrus, and males. These results suggest gonadal steroid hormones influence adrenoreceptor-mediated control of vasopressin secretion, MABP, and HR.

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Role of vasopressin V1A receptor in the urethral closure reflex in rats

AJP Renal Physiology ◽

10.1152/ajprenal.00658.2010 ◽

2011 ◽

Vol 300 (4) ◽

pp. F976-F982 ◽

Cited By ~ 5

Author(s):

Hiroyuki Ueno ◽

Masako Kuno ◽

Yasushi Shintani ◽

Izumi Kamo

Keyword(s):

Spinal Cord ◽

Pressure Rise ◽

Physiological Role ◽

Female Rats ◽

Reflex Response ◽

Abdominal Pressure ◽

Intravesical Pressure ◽

Urethral Closure ◽

Urethral Resistance ◽

Vasopressin V1a Receptor

An enhanced urethral closure reflex via the spinal cord is related to urethral resistance elevation during increased abdominal pressure. However, with the exception of monoamines, neurotransmitters modulating this reflex are not understood. We investigated whether the vasopressin V1A receptor (V1AR) is involved in the urethral closure reflex in urethane-anesthetized female rats. V1AR mRNA was highly expressed among the vasopressin receptor family in the total RNA purified from lamina IX in the spinal cord L6–S1 segment. In situ hybridization analysis of the spinal L6–S1 segment confirmed that these positive signals from the V1ARs were only detected in lamina IX. Intrathecally injected Arg8-vasopressin (AVP), an endogenous ligand, significantly increased urethral resistance during an intravesical pressure rise, and its effect was blocked by the V1AR antagonist. AVP did not increase urethral resistance in rats in which the pelvic nerves were transected bilaterally. Urethral closure reflex responses to the intravesical pressure rise increased by up to threefold compared with the baseline response after AVP administration in contrast to no increase by vehicle. In addition, intravenously and intrathecally injected V1AR antagonists decreased urethral resistance. These results suggest that V1AR stimulation in the spinal cord enhances the urethral closure reflex response, thereby increasing urethral resistance during an abdominal pressure rise and that V1AR plays a physiological role in preventing urine leakage.

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Oxytocin Reduces Intravesical Pressure in Anesthetized Female Rats: Action on Oxytocin Receptors of the Urinary Bladder

Frontiers in Physiology ◽

10.3389/fphys.2020.00382 ◽

2020 ◽

Vol 11 ◽

Author(s):

Eduardo M. Cafarchio ◽

Luiz A. da Silva ◽

Luciana C. Auresco ◽

Itatiana F. Rodart ◽

Janaina S. de Souza ◽

...

Keyword(s):

Urinary Bladder ◽

Female Rats ◽

Intravesical Pressure ◽

Oxytocin Receptors

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Brain stem and cerebellar lesions in female rats. II. lordosis reflex

Brain Research ◽

10.1016/0006-8993(76)90072-x ◽

1976 ◽

Vol 106 (1) ◽

pp. 47-56 ◽

Cited By ~ 24

Author(s):

Doan T. Modianos ◽

Donald W. Pfaff

Keyword(s):

Brain Stem ◽

Female Rats ◽

Cerebellar Lesions

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Intravesical pressure (IP) alterations evoked by carbachol into the fourth brain ventricle (4th V) in female rats

Autonomic Neuroscience ◽

10.1016/j.autneu.2011.05.036 ◽

2011 ◽

Vol 163 (1-2) ◽

pp. 49

Author(s):

E.M. Cafarchio ◽

R.L. Almeida ◽

C.A. Ogihara ◽

I.H. Saviolli ◽

E. Colombari ◽

...

Keyword(s):

Female Rats ◽

Intravesical Pressure ◽

Brain Ventricle

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Urethral closure mechanisms under sneeze-induced stress condition in rats: a new animal model for evaluation of stress urinary incontinence

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00010.2003 ◽

2003 ◽

Vol 285 (2) ◽

pp. R356-R365 ◽

Cited By ~ 84

Author(s):

Izumi Kamo ◽

Kazumasa Torimoto ◽

Michael B. Chancellor ◽

William C. de Groat ◽

Naoki Yoshimura

Keyword(s):

Urinary Incontinence ◽

Stress Condition ◽

Female Rats ◽

Urinary Continence ◽

Abdominal Pressure ◽

Intravesical Pressure ◽

External Urethral Sphincter ◽

Urinary Leakage ◽

Induced Stress ◽

Urethral Closure

The urethral closure mechanism under a stress condition induced by sneezing was investigated in urethane-anesthetized female rats. During sneezing, while the responses measured by microtip transducer catheters in the proximal and middle parts of the urethra increased, the response in the proximal urethra was almost negligible when the bladder response was subtracted from the urethral response or when the abdomen was opened. In contrast, the response in the middle urethra during sneezing was still observed after subtracting the bladder response or after opening the abdomen. These responses in the middle urethra during sneezing were significantly reduced ∼80% by bilateral transection of the pudendal nerves and the nerves to the iliococcygeous and pubococcygeous muscles but not by transection of the visceral branches of the pelvic nerves and hypogastric nerves. The sneeze leak point pressure was also measured to investigate the role of active urethral closure mechanisms in maintaining total urethral resistance against sneeze-induced urinary incontinence. In sham-operated rats, no urinary leakage was observed during sneeze, which produced an increase of intravesical pressure up to 37 ± 2.2 cmH2O. However, in nerve-transected rats urinary leakage was observed when the intravesical pressure during sneezing exceeded 16.3 ± 2.1 cmH2O. These results indicate that during sneezing, pressure increases elicited by reflex contractions of external urethral sphincter and pelvic floor muscles occur in the middle portion of the urethra. These reflexes in addition to passive transmission of increased abdominal pressure significantly contribute to urinary continence mechanisms under a sneeze-induced stress condition.

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