The role of the hypothalamic β-adrenergic system in controlling the LH rise in short-term castrated rats

1987 ◽  
Vol 114 (2) ◽  
pp. 167-172 ◽  
Author(s):  
M. H. Al-Hamood ◽  
D. P. Gilmore ◽  
C. A. Wilson ◽  
P. Tuohy-Jones ◽  
S. Drummond ◽  
...  
Keyword(s):  
Adrenergic Receptor ◽  
Concomitant Administration ◽  
Inhibitory Effect ◽  
Adrenergic System ◽  
Receptor Subtypes ◽  
Short Term ◽  
Pharmacological Agents ◽  
Inhibitory Component ◽  
Lh Release

ABSTRACT Intraventricular infusions of adrenaline and various pharmacological agents acting on β-adrenergic receptor subtypes were carried out in rats orchidectomized 16 h previously. Infusions (10 μl) of solutions containing the drugs were administered under anaesthesia induced with alphaxalone and alphadolone. Levels of LH were measured in plasma collected immediately before and at predetermined intervals after the infusion. The acute rise in LH levels after castration was increased still further by isoprenaline (a mixed β1- and β2-agonist), fenoterol (a β2-agonist) and atenolol (a β1-antagonist). In contrast, prenalterol (a β1-agonist) and (2RS,3RS)-3-isopropylamino-1-(7-methylindan-4-yloxy)butan-2-ol (ICI 118 551) (a selective β2-antagonist) were inhibitory to LH release. Adrenaline itself, salbutamol (another selective β2-agonist), propranolol (a mixed β-antagonist) and metoprolol (a β1-antagonist) did not significantly alter plasma LH concentrations at the doses administered. The stimulatory effect of isoprenaline on LH release was partially reduced when given together with ICI 118 551, but was not affected when administered simultaneously with atenolol. The inhibitory effect of ICI 118 551 was, however, prevented by concomitant administration with fenoterol, as was that of prenalterol when infused with atenolol. The results suggest that the hypothalamic mediation of the short-term changes in LH release in response to castration is exerted, at least in part, through the activation of a β2-stimulatory component and the suppression of a β1-inhibitory component. J. Endocr. (1987) 114, 167–172

Evidence for a stimulatory β-adrenergic component in the release of the ovulatory LH surge in pro-oestrous rats

1985 ◽  
Vol 106 (2) ◽  
pp. 143-151 ◽  
Author(s):  
M. H. Al-Hamood ◽  
D. P. Gilmore ◽  
C. A. Wilson
Keyword(s):  
Adrenergic Receptor ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Adrenergic System ◽  
Receptor Subtypes ◽  
Inhibitory Effects ◽  
Pharmacological Agents ◽  
Lh Surge ◽  
Pentobarbitone Sodium ◽  
Lh Release

ABSTRACT The effect on ovulation of intraventricular infusions of noradrenaline, adrenaline and various pharmacological agents acting on the adrenergic receptor subtypes were investigated in cyclic female rats on the day of pro-oestrus. The inhibitory effects on ovulation of the different infusions were monitored by administering the drugs before 11.00 h (several hours before the critical period for the ovulatory LH surge). In experiments designed to show how the drugs under investigation might stimulate ovulation, pentobarbitone sodium (35 mg/kg) was given at 14.30 h; this anaesthetic inhibits ovulation and its effects can be overcome by substances that advance the preovulatory LH surge. Noradrenaline (an α-agonist) stimulated ovulation when administered on the morning of pro-oestrus to rats injected with pentobarbitone early in the afternoon of the same day. Phenoxybenzamine and phentolamine (non-selective α-antagonists) and clonidine (a selective α2-agonist) all inhibited ovulation when infused on the morning of pro-oestrus. Yohimbine (a moderately selective α2-antagonist) neither stimulated nor inhibited ovulation. Both isoprenaline (a non-selective β-agonist) and fenoterol (a selective β2-agonist) stimulated ovulation in pentobarbitone-treated rats when administered on the morning of pro-oestrus and fenoterol was also able to overcome the pentobarbitone block when infused later in the afternoon. Propranolol (a non-selective β-antagonist) and metoprolol (a selective β1-antagonist) were stimulatory only when administered in the afternoon. Adrenaline (both an α- and β-agonist), prenalterol (a selective β1-agonist), atenolol (a selective β1-antagonist) and ICI 118, 551 (a selective β2-antagonist) neither stimulated nor inhibited ovulation. The effect of intraventricular infusions of two selected β-adrenergic drugs was also investigated in ovariectomized rats primed with 2 μg oestradiol benzoate 48 h previously. Isoprenaline and fenoterol were able to stimulate LH release at 40 and 10 min respectively after their administration. These results suggest a possible involvement of a stimulatory β2-adrenergic component in the neural regulation of the preovulatory LH surge along with the well-documented α-stimulatory component, which together may mask the possible inhibitory effects of a β1-adrenergic system. J. Endocr. (1985) 106, 143–151

scholarly journals Role of beta-adrenergic receptor subtypes in pig uterus contractility with inflammation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Barbara Jana ◽  
Jarosław Całka
Keyword(s):  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Domestic Animals ◽  
Inhibitory Effect ◽  
Receptor Subtypes ◽  
Beta Adrenergic Receptor ◽  
Pharmacological Modulation ◽  
Uterine Inflammation ◽  
Myometrial Contractility

AbstractUterine inflammation is a very common and serious condition in domestic animals. To development and progression of this pathology often lead disturbances in myometrial contractility. Participation of β1-, β2- and β3-adrenergic receptors (ARs) in noradrenaline (NA)-influenced contractility of the pig inflamed uterus was studied. The gilts of SAL- and E.coli-treated groups were administered saline or E.coli suspension into the uterine horns, respectively. Laparotomy was only done in the CON group. Compared to the period before NA administration, this neurotransmitter reduced the tension, amplitude and frequency in uterine strips of the CON and SAL groups. In the E.coli group, NA decreased the amplitude and frequency, and these parameters were lower than in other groups. In the CON, SAL and E.coli groups, β1- and β3-ARs antagonists in more cases did not significantly change and partly eliminated NA inhibitory effect on amplitude and frequency, as compared to NA action alone. In turn, β2-ARs antagonist completely abolished NA relaxatory effect on these parameters in three groups. Summarizing, NA decreases the contractile amplitude and frequency of pig inflamed uterus via all β-ARs subtypes, however, β2-ARs have the greatest importance. Given this, pharmacological modulation of particular β-ARs subtypes can be used to increase inflamed uterus contractility.

beta-Receptor influence on lung vasoconstrictor responses to hypoxia and humoral agents

1977 ◽  
Vol 43 (4) ◽  
pp. 612-616 ◽  
Author(s):  
R. J. Porcelli ◽  
A. T. Viau ◽  
N. E. Naftchi ◽  
E. H. Bergofsky
Keyword(s):  
Adrenergic Receptor ◽  
Adrenergic System ◽  
Hypercapnic Acidosis ◽  
Pulmonary Tissue ◽  
Beta Adrenergic ◽  
Vascular Responses ◽  
Adenosine Cyclic Monophosphate ◽  
Adrenergic Activity ◽  
Camp Levels

The role of the adrenergic receptor in mediating pulmonary vascular responses to gaseous and humoral agents was investigated by use of epinephrine injections in the perfused feline pulmonary circulation. Alteration of the balance between alpha- and beta-adrenergic activity was quantified by measurement of decreasing vasoconstrictor activity to epinephrine and rising lobar tissue 3′,5′-adenosine cyclic monophosphate (cAMP) levels. The increased beta-adrenergic activity thus generated was associated with marked reductions in the pulmonary vasoconstrictor responses to hypoxia, hypercapnic acidosis, and histamine, but not to serotonin. Repeated pulmonary vasodilations or increases in blood, but not pulmonary tissue, levels of cAMP induced by theophylline doses, which would not necessarily affect the beta-adrenergic activity, did not alter the pulmonary vasoconstrictor responses to hypoxia, hypercapnia, or histamine. These data support the significant role which the adrenergic system plays in mediating pulmonary vasoconstrictor responses to certain specific gaseous and humoral agents, and the specificity with which this mediation occurs serves to link hypoxia and histamine together so that the latter could serve as a mediator of the former.

scholarly journals The Role of NMDA Receptor Subtypes in Short-Term Plasticity in the Rat Entorhinal Cortex

2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Sophie E. L. Chamberlain ◽  
Jian Yang ◽  
Roland S. G. Jones
Keyword(s):  
Entorhinal Cortex ◽  
Glutamate Release ◽  
Receptor Subtypes ◽  
Short Term ◽  
Low Frequencies ◽  
Short Term Plasticity ◽  
Whole Cell Patch Clamp ◽  
Layer V ◽  
Presynaptic Nmda Receptors

We have previously shown that spontaneous release of glutamate in the entorhinal cortex (EC) is tonically facilitated via activation of presynaptic NMDA receptors (NMDAr) containing the NR2B subunit. Here we show that the same receptors mediate short-term plasticity manifested by frequency-dependent facilitation of evoked glutamate release at these synapses. Whole-cell patch-clamp recordings were made from layer V pyramidal neurones in rat EC slices. Evoked excitatory postsynaptic currents showed strong facilitation at relatively low frequencies (3 Hz) of activation. Facilitation was abolished by an NR2B-selective blocker (Ro 25-6981), but unaffected by NR2A-selective antagonists (Zn2+, NVP-AAM077). In contrast, postsynaptic NMDAr-mediated responses could be reduced by subunit-selective concentrations of all three antagonists. The data suggest that NMDAr involved in presynaptic plasticity in layer V are exclusively NR1/NR2B diheteromers, whilst postsynaptically they are probably a mixture of NR1/NR2A, NR1/NR2B diheteromers and NR1/NR2A/NR2B triheteromeric receptors.

Role of adrenergic receptor subtypes in the control of human placental blood vessels

2003 ◽  
Vol 66 (2) ◽  
pp. 166-171 ◽  
Author(s):  
BÉla Endre Resch ◽  
Eszter Ducza ◽  
RÓbert GÁspÁr ◽  
George Falkay
Keyword(s):  
Blood Vessels ◽  
Adrenergic Receptor ◽  
Receptor Subtypes ◽  
Placental Blood

Role of supraspinal and spinal α1-adrenergic receptor subtypes in micturition reflex in conscious rats

2010 ◽  
Vol 299 (4) ◽  
pp. F785-F791 ◽  
Author(s):  
Masaru Yoshizumi ◽  
Kazumasa Matsumoto-Miyai ◽  
Akihiko Yonezawa ◽  
Masahito Kawatani
Keyword(s):  
Spinal Cord ◽  
Receptor Antagonist ◽  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Intrathecal Injection ◽  
Receptor Subtypes ◽  
Lumbosacral Spinal Cord ◽  
Micturition Reflex ◽  
Conscious Rats

α1-Adrenergic receptor subtypes are widely distributed in the central nervous system and are involved in autonomic functions such as micturition. We investigated the presence and the role of supraspinal and/or spinal α1-adrenergic receptors in modulating the micturition reflex in conscious female Wistar rats. The expression of α1-adrenergic receptor subtypes in rat brain and lumbosacral spinal cord was studied using RT-PCR. Continuous-infusion cystometrograms were obtained in conscious rats, and α1-adrenergic receptor antagonists were administered via intracerebroventricular or intrathecal routes. The mRNA expression of α1A-, α1B-, and α1D-adrenergic receptors was detected in rat brain (midbrain and pons) and lumbosacral spinal cord (dorsal and ventral parts of spinal cord). In addition, intracerebroventricular injection of the α1-adrenergic receptor antagonist tamsulosin (1–10 μg), the selective α1A-adrenergic receptor antagonist silodosin (1–10 μg), and the selective α1D-adrenergic receptor antagonist BMY 7378 (1–10 μg) significantly prolonged the intercontraction interval (ICI) but did not alter maximum voiding pressure (MVP). Although intrathecal injection of BMY 7378 (0.0001–10 μg) did not affect ICI, tamsulosin and silodosin prolonged ICI in a dose-dependent manner. MVP was significantly reduced by intrathecal injection of tamsulosin (10 μg) but not by silodosin or BMY 7378 (0.0001–10 μg). Supraspinal α1A- and α1D-adrenergic receptors are apparently important for the regulation of reflex-bladder activity in conscious rats. Noradrenergic projection from the brain stem to the lumbosacral spinal cord may promote the afferent limb rather than the efferent limb of the micturition reflex pathway via α1A-adrenergic receptors.

scholarly journals Role of α 2 -Adrenergic Receptor Subtypes in the Acute Hypertensive Response to Hypertonic Saline Infusion in Anephric Mice

Hypertension ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 609-613 ◽  
Author(s):  
Konstantinos P. Makaritsis ◽  
Conrado Johns ◽  
Irene Gavras ◽  
Haralambos Gavras
Keyword(s):  
Hypertonic Saline ◽  
Adrenergic Receptor ◽  
Saline Infusion ◽  
Receptor Subtypes ◽  
Hypertonic Saline Infusion
Sign in / Sign up

Export Citation Format

Share Document