Pharmacological investigations into the effects of histamine and histamine analogs on guinea pig and rat uterus

A Comparison of Pain Scores in Dysmenorrheic Patients With or Without Dyspeptic Symptoms

Introductıon: Dysmenorrhea attacks may be accompanied by extragenital symptoms such as nausea, vomiting, diarrhea, headache and leg pain and by emotional symptoms such as tension and irritability. Therefore, we think that dysmenorrheic symptoms may be more severe in patients with dyspeptic symptoms. The purpose of this study was to determine whether pain scores would differ between dysmenorrheic patients with or without dyspeptic symptoms.

METHODS

Patients presenting to the emergency department with dysmenorrhea attacks and volunteering to participate were included in this case-control study. Subjects with dyspeptic symptoms were enrolled as the case group and those without dyspeptic symptoms were enrolled as the control group. Participants were administered the Faces Pain Scale and a questionnaire involving demographic characteristics.

RESULTS

Pain scores on arrival were higher in the case group than in the control group (4.20 ± 0.71, 3.70 ± 0.74, n=30, p=0.011). A significant difference was observed between pain scores on arrival and at discharge in both the control and case groups. A decrease in pain scores was determined in all the subjects in the case group, while no change was observed in three volunteers in the control group.

CONCLUSIONS

We conclude that pain is significantly more severe in dysmenorrheic patients with dyspeptic symptoms.

Extra and intracellular calcium signaling pathway(s) differentially regulate histamine-induced myometrial contractions during early and mid-pregnancy stages in buffaloes (Bubalus bubalis)

This study examines the differential role of calcium signaling pathway(s) in histamine-induced uterotonic action during early and mid-pregnancy stages in buffaloes. Compared to mid pregnancy, tonic contraction, amplitude and mean-integral tension were significantly increased by histamine to produce myometrial contraction during early pregnancy with small effects on phasic contraction and frequency. Although uterotonic action of histamine during both stages of pregnancy is sensitive to nifedipine (a L-type Ca²⁺ channels blocker) and NNC55-0396 (T-type Ca²⁺ channels blocker), the role of extracellular calcium seems to be more significant during mid-pregnancy as in this stage histamine produced only 9.38±0.96% contraction in Ca²⁺ free-RLS compared to 21.60±1.45% in uteri of early pregnancy stage. Intracellular calcium plays major role in histamine-induced myometrial contraction during early pregnancy as compared to mid pregnancy, as in the presence of cyclopiazonic acid (CPA) Ca²⁺-free RLS, histamine produced significantly higher contraction in myometrial strips of early-pregancy in comparison to mid-pregnancy (10.59±1.58% and 3.13±0.46%, respectively). In the presence of U-73122, the DRC of histamine was significantly shifted towards right with decrease in maximal effect (E_max) only in early pregnancy suggesting the predominant role of phospholipase-C (PL-C) in this stage of pregnancy.

Challenge with ovalbumin antigen increases uterine and cervical contractile activity in sensitized guinea pigs

OBJECTIVE

The aims of this study were to investigate the effects of ovalbumin challenge on uterine and cervical contractility, intrauterine pressure, and uterine electromyography activity in sensitized guinea pigs.

STUDY DESIGN

Guinea pigs were sensitized by injection of ovalbumin-aluminum hydroxide suspension. Control animals were injected with the aluminum hydroxide suspension only. On days 55-57 of pregnancy, longitudinal uterine and cervical strips from guinea pigs were prepared for isometric tension recording. Nonpregnant guinea pigs were outfitted with telemetric transducers to record intrauterine pressure and uterine electromyography.

RESULTS

Ovalbumin significantly increased contractility of uterine and cervical strips from sensitized versus nonsensitized animals. These effects were abolished by histamine H(1) receptor antagonist in uterine strips and by histamine H(1) receptor antagonist and a mast cell stabilizer in cervical strips from sensitized animals. Cyclooxygenase and 5-lipoxygenase inhibitors had no significant effect on the response to ovalbumin. Treatment with ovalbumin in vivo significantly increased intrauterine pressure and uterine electromyography activity in sensitized but not in nonsensitized, animals.

CONCLUSION

Our findings indicate that type I hypersensitivity reactions may be important in mediating uterine contractility in pregnant and nonpregnant states.

Degranulation of uterine mast cell modifies contractility of isolated myometrium from pregnant women

OBJECTIVE

This study was undertaken to test that uterine mast cell degranulation alters human myometrial contractility in vitro and to define what mediators are involved in this process.

STUDY DESIGN

Longitudinal myometrial strips prepared from biopsy specimen obtained from the lower uterine segment of women at preterm and term gestation (with and without labor) were studied. Contractile responses to compound 48/80, a mast cell degranulator, were compared in the absence or presence of a mast cell stabilizer, H 1 and H 2 receptor antagonists, cyclooxygenase, and lipoxygenase inhibitors.

RESULTS

Compound 48/80 increased myometrial contractility in all groups. The mast cell stabilizer cromolyn inhibited contractility, whereas the cyclooxygenase inhibitor ibuprofen, the H 1 -receptor antagonist S(+)-chlorpheniramine maleate, but not the H 2 antagonist cimetidine, only slightly attenuated this effect. The lipoxygenase inhibitor linoleyl hydroxamic acid augmented the responses to compound 48/80 in the preterm but not in the term group.

CONCLUSION

Uterine mast cell degranulation, or the effects of their mediators, can modulate uterine contractility during pregnancy.

Induction of premature labor and delivery by allergic reaction and prevention by histamine H1 receptor antagonist

OBJECTIVE

The purpose of this study was to determine whether type I hypersensitivity can induce preterm labor and delivery that may be prevented by the administration of an H 1 receptor antagonist or a mast-cell stabilizer.

STUDY DESIGN

At days 40 through 50 of gestation, ovalbumin-sensitized guinea pigs that had not been treated or had been pretreated with an H 1 receptor antagonist (ketotifen) or a mast-cell stabilizer (cromolyn sodium) were challenged with either ovalbumin or saline solution. Nonsensitized guinea pigs were challenged with ovalbumin.

RESULTS

The duration of gestation was significantly shorter in sensitized animals that were challenged with ovalbumin than in the other groups. Pretreatment with ketotifen significantly increased the duration of pregnancy in sensitized animals, compared with untreated animals. Cromolyn sodium had no effect.

CONCLUSION

An allergic reaction can induce premature labor/delivery, and pretreatment with histamine H 1 receptor antagonist can prevent it. These observations provide evidence of a novel mechanism of disease for premature labor and delivery.

Effect of histamine on phasic and tonic contractions of isolated uterine tissue from pregnant women

OBJECTIVE

To enhance our understanding of the uterotonic effect of histamine, we compared the effects of histamine on spontaneous phasic and tonic contractile activity of uterine strips from term pregnant nonlaboring women.

STUDY DESIGN

Longitudinal uterine strips were used from the lower uterine segment of term pregnant nonlaboring women undergoing elective cesarean section. The concentration-response relationship to histamine (10(-8) to 10(-4) mol/L) was determined in spontaneously contracting strips or in strips contracted tonically with a protein kinase C activator (-)-indolactam V in the presence of H(1) receptor antagonist (S[+]-chlorpheniramine maleate), H(2) receptor antagonist (cimetidine), or solvent.

RESULTS

Histamine increased spontaneous phasic myometrial contractions in a concentration-dependent manner. H(1), but not H(2), receptor antagonist significantly attenuated the response to histamine. Histamine significantly reduced tonic contractions of uterine strips induced by indolactam V. H(1) histamine receptor antagonist abolished relaxation, whereas H(2) histamine receptor antagonist had no effect.

CONCLUSION

Histamine increases spontaneous, but inhibits tonic, contractions of uterine strips from term pregnant nonlaboring women. Both effects are mediated through activation of H(1) receptors.

Endogenous mast cell degranulation modulates cervical contractility in the guinea pig

OBJECTIVE

The purpose of this study was to investigate the effect of endogenous mast cell degranulation on the contractility of isolated cervical strips from nonpregnant and pregnant guinea pigs.

STUDY DESIGN

Longitudinal cervical strips from nonpregnant and pregnant (mid and term) guinea pigs were used for isometric tension recording. Responses to the mast cell degranulating agent, compound 48/80, were compared in the absence or presence of different inhibitors and receptor antagonists. Concentration-response curves were obtained to histamine and 5-hydroxytryptamine in strips that were incubated with antagonists or solvent.

RESULTS

Compound 48/80 and histamine significantly increased contractility of cervical strips in all 3 groups of animals. The inhibitor of mast cell degranulation significantly reduced responses to compound 48/80 and histamine-1 receptor antagonist reduced responses to histamine in all 3 groups. Histamine-1 receptor antagonist significantly inhibited responses to compound 48/80 in nonpregnant and mid pregnant guinea pigs. Histamine-2 receptor antagonist did not alter responses to compound 48/80 nor to histamine. The receptor antagonist 5-hydroxytryptamine-2 significantly inhibited cervical contractility that was induced by compound 48/80 in tissues from mid pregnant and term pregnant guinea pigs. Lipoxygenase inhibitor was effective in mid pregnant guinea pigs. Cyclooxygenase inhibitor, 5-hydroxytryptamine, and a combination of lipoxygenase and cyclooxygenase inhibitors had no effect on cervical contractility.

CONCLUSION

The degranulation of mast cells releases histamine and other mediators that stimulate cervical contractility through histamine-1 receptors. Cervical infiltration and modulation of contractility by mast cells may play an important physiologic and/or pathologic role in the control of cervical function during pregnancy.

Modulation of rat uterine contractility by mast cells and their mediators

OBJECTIVE

This study was designed to test the possibility that mast cells play a role in the regulation of uterine contractility.

STUDY DESIGN

Histamine and rat mast cell protease II levels were determined by radioenzymatic assay and standard radial immunodiffusion techniques, respectively, in uterine tissues from Wistar rats with timed pregnancies. Isolated uterine strips from nonsensitized and ovalbumin-sensitized nonpregnant and pregnant Wistar rats were used for isometric tension recording. Contractile responses to compound 48/80, carbachol, ovalbumin, normal rabbit serum, antirat immunoglobulin E, and 5-hydroxytryptamine were obtained. Antagonists methysergide, ketanserin, 5,8,11, 14-eicosatetraynoic acid, diphenhydramine, and sodium meclofenamate were also used.

RESULTS

Tissue levels of rat mast cell protease II and histamine were decreased during delivery compared with prepartum and postpartum levels. Carbachol and compound 48/80 stimulated uterine contractility, and responses were highest during late gestation (day 16 to term). Responses to ovalbumin of uterine tissues in rats sensitized to the antigen were highest at midpregnancy and decreased during the last 10 days of gestation. Ovalbumin challenge in vitro increased the frequency and magnitude of contractions in tissues from ovalbumin-sensitized rats. Compound 48/80 and antirat immunoglobulin E stimulated contractility in both control and sensitized rats. None of the antagonists prevented the contractile responses.

CONCLUSIONS

Activation of mast cells is an effective mechanism for stimulation of uterine contractility and may play an important role in the control of term and preterm parturition.

Histamine mediates the muscle layer-specific responses in the isolated swine myometrium

To clarify the role of histamine in uterine contractility, the effect of this biogenic amine on the myometrium of cyclic mature gilts was investigated by an isometric tension recording study in vitro. In addition, using crude membrane preparations isolated from the longitudinal (LM) and circular muscle (CM), the distribution of H1 histamine receptors was characterized by 3H-pyrilamine binding assay. Histamine caused a tetrodotoxin-resistant contractile response of LM and CM in Krebs solution, but LM (-logEC50 = 6.34) was more sensitive than CM (-logEC50 = 5.4). Pyrilamine decreased the excitatory response of histamine in both muscle layers. In pyrilamine-treated LM, a high concentration of histamine (1-30 microM) caused a slight inhibition of spontaneous contraction, and this inhibition was abolished by ranitidine. On the other hand, histamine did not cause any inhibition in the pyrilamine-treated CM preparations. Dimaprit (10-300 microM) concentration-dependently inhibited the spontaneous contraction of LM but not of CM. In the presence of pyrilamine and ranitidine, N alpha-methylhistamine, even at 10 microM, did not affect the spontaneous and electrical field stimulation (5Hz)-induced contraction of LM and CM layers. Specific 3H-pyrilamine binding sites were distributed heterogeneously in the swine myometrium. The maximum number of binding sites in LM (132.5 +/- 9.9 fmol/mg protein, n = 10) was 2.5 times higher than that in CM (52.2 +/- 3.2 fmol/mg protein, n = 6). These results indicate that there is a muscle layer-dependent difference of histamine-induced response in the swine myometrium. In the LM layer, histamine acts on both H1 and H2 histamine receptors, and causes contraction (via H1 receptors at a low concentration) or relaxation (via H2 receptors at a high concentration in the presence of pyrilamine). However, histamine causes only a contraction in the CM layer, likely the result of the absence of H2 histamine receptors. Histamine-induced contraction is conspicuous in the LM layer, because of the heterogeneous distribution of H1-receptors between LM and CM.

Effect of histamine on the longitudinal and circular muscle of the oestrogen dominated rat uterus

The response of the longitudinal and circular myometrial strips to histamine was studied in oestrogen-treated rats. Histamine produced a dose-related inhibitory response in KCl-contracted longitudinal and circular uterine strips. Histamine was equipotent in producing the relaxant response but the maximal effect achieved in the longitudinal muscle was higher than the circular one. Ranitidine antagonized the histamine-induced relaxation with a similar dose ratio in both longitudinal and circular strips. Clemizole and reserpine treatment did not produce any modification of the dose-response curve to histamine. In the longitudinal and circular strips which were not preconstricted by KCl, neither histamine nor 2-pyridylethylamine, even in strips pretreated with ranitidine, produced any effect when added to the organ bath. Our results show that the response of histamine in both longitudinal and circular uterine layers of the oestrogen-treated rats are mediated exclusively by histamine H2-receptors.

Effect of histamine and histamine analogues on human isolated myometrial strips

1. The effect of histamine and histamine H1- and H2-receptor agonists on isolated myometrium strips of premenopausal women has been examined. The effect of acetylcholine was also determined. 2. Histamine, 2-pyridylethylamine, 4-methylhistamine and acetylcholine, but not dimaprit, produced a concentration-related contractile response in human isolated myometrial strips. Histamine also produced a further contraction in human isolated myometrial strips precontracted with KCl (55 mM). 3. The contractile response to histamine was antagonized by the histamine H1-receptor antagonist, clemizole (0.1 microM) but was potentiated by the histamine H2-receptor antagonist, ranitidine (10 microM). Clemizole (0.1 nM to 10 nM) competitively antagonized the contractile effect of 2-pyridylethylamine (- log KB = 10.5 +/- 0.5). The concentration-response curve for acetylcholine was displaced to the right by atropine 0.1 microM. 4. Atropine (0.1 microM), propranolol (0.1 microM), prazosin (0.1 microM) and indomethacin (1 microM) failed to modify the contractile response to histamine. 5. In human isolated myometrial strips precontracted with KCl (55 mM), clemizole at 1 microM completely abolished the contractile response to histamine and revealed a concentration-dependent relaxation. Dimaprit alone and 4-methylhistamine (in the presence of clemizole), produced concentration-related relaxation with a magnitude similar to that in response to histamine. The relaxant response to dimaprit was antagonized by ranitidine. 6. It is concluded that human isolated uterine strips possess histamine H1- and H2-receptors: the former mediating contraction and the latter relaxation. The predominant response to histamine in this tissue is contraction.

Influence of hormonal treatment on the response of the rat isolated uterus to histamine and histamine receptor agonists

The response of the isolated uterus to histamine and histamine agonists was investigated in progesterone- and oestrogen-treated rats. The uterine inhibitory responses to histamine and 4-methylhistamine (a histamine H2 receptor agonist) were similar in KCl-contracted uteri from progesterone- and oestrogen-treated rats. The histamine H1 receptor agonist, 2-pyridyl-ethylamine, produced a relaxant response only in progesterone dominant uterus. This was inhibited by the histamine H1 receptor antagonist. In the rat isolated uterus which was not preconstricted by KCl, neither histamine, 4-methylhistamine, nor 2-pyridyl-ethylamine produced any effect in the presence or absence of ranitidine. Ranitidine competitively antagonized the histamine-relaxant uterine response in oestrogen-treated rats (pA2 = 7.21 (6.83-7.58)), but not in progesterone-treated rats, except in the presence of clemizole (10(-7) M) when the pA2 value of ranitidine against histamine was similar to that obtained in oestrogen-treated rats (pA2 = 6.74 (6.64-6.85)). These results indicate that treatment with ovarian steroids influences responses mediated by the histamine receptors of the isolated rat uterus. Both histamine H2 and H1 receptors contribute to the uterine inhibitory effect of histamine in progesterone-treated rats.

The actions of histamine on the separated layers of the guinea-pig uterus: the influence of ovarian steroids

The effects of histamine have been studied on separated circular and longitudinal myometrial layers from the guinea-pig. Virgin guinea-pigs in dioestrus were (1) untreated, (2) treated for 14 days thrice weekly with oestradiol cypionate 20 micrograms/kg s.c., or (3) treated as in (2) but in addition with progesterone 3 mg/animal s.c. daily for 4 days before use. Preparations were field-stimulated (60 V 2 ms 30 Hz for 5 s every 100 s) to elicit regular contractions. Histamine was equipotent in producing enhancement of evoked contractions of circular myometrium from animals in each treatment group (pD2 = 5.03, 5.05 and 4.95 in groups 1, 2 & 3 respectively), and enhanced contractility in all but two longitudinal myometrial preparations. Treatment with oestradiol alone, and with oestradiol and progesterone following oestradiol priming enhanced the magnitude of maximal response and produced a small decrease in the potency of histamine on the longitudinal myometrium. pA2 estimates for mepyramine as an antagonist were similar (8.6) in preparations of longitudinal myometrium from each group of animals. Metiamide (1-10 mumol/l) did not antagonise the effects of histamine in this layer. These results, taken together, indicate that ovarian steroids act selectively on the longitudinal myometrial layer to amplify the action of histamine, but do not alter the histamine receptor subtype which in this layer is exclusively H1.

Pharmacological investigation into the effects of histamine and histamine analogues on guinea-pig and rat colon in vitro

The effects of histamine and specific histamine agonists has been examined on isolated longitudinal colon strips of guinea-pig and rat. Histamine and 2-pyridyl-ethylamine but not 4 methylhistamine produced a concentration-related contractile response in the guinea-pig colon. The H1-antagonist clemizole antagonized competitively the effect of histamine but the H2-antagonist ranitidine did not modify the dose-response curve to histamine in the guinea-pig colon. Atropine, hexamethonium, prazosin and propranolol failed to modify the contractile response to histamine. Tone induced with KCl in guinea-pig isolated colon was not modified by histamine agonists even in tissues pretreated with clemizole or ranitidine. Histamine and histamine analogues were without effect on the isolated longitudinal strip of the rat colon. It is concluded that histamine produced dose-dependent contractions of the guinea-pig colon due to direct activation of H1-histamine receptors. There is no evidence in favour of the existence of H2-histamine receptors in this preparation. The lack of effect of histamine agonists in rat colon strip argues against the existence of histamine receptors in this preparation.

The zoapatle. X. The in vitro effect of zoapatle aqueous crude extract (ZACE) and histamine upon rat and guinea pig uterine strips

In vitro histamine response in rat and guinea pig uterine strips was similar to the one observed with zoapatle aqueous crude extract (ZACE). The relaxing effect elicited by ZACE/tomentosa on the in vitro rat uterine strips was not mediated by activation of H-2 histamine receptors; moreover, the increase on uterine contractility elicited by ZACE/tomentosa on the in vitro guinea pig uterine strip was not mediated through the activation of H-1 histamine receptors.

The inhibitory effect of histamine on the motility of rat uterus in vivo

The experiments concerned the effects of histamine and its analogs 4-methylhistamine and 2-pyridyl-ethylamine on the spontaneous activity of the estrogenized rat uterus in vivo. These agonists given intravenously inhibited uterine activity. Histamine and 4-methylhistamine, but not 2-pyridyl ethylamine, produced this effect in a dose-dependent manner. The ability of histamine to reduce uterine activity was lowered by pretreatment with reserpine, adrenalectomy or 6-hydroxydopamine. The effect of 4-methylhistamine also was reduced by reserpine or adrenalectomy. The inhibitory effect of 2-(2-pyridyl) ethylamine was completely abolished by reserpine or adrenalectomy. Cimetidine attenuated the residual inhibitory effect of histamine in reserpinized rats. These results suggest that the uterine inhibitory action of histamine and 4-methylhistamine is mediated through catecholamine release and direct stimulation of the H2-receptors. The effect of 2-(2-pyridyl) ethylamine is only mediated by release catecholamine.