The Effect of Histamine on the Rat Oestrous Cycle

Intracerebroventricular (icv) administration of histamine (80-120mg) to adult Wistar rats was found to induce irregular cycles and, at times, persistent oestrous cycle when administered at different stages of the cycle. Cimetidine (50 mg/kg), a H2-receptor antagonist, administered intraperitoneally (ip) produced a transient change in the cycle, which returned to normal rhythm after a day or two. Triprolidine (50 mg/kg; ip), a H1-receptor antagonist, showed no changes in the oestrous rhythm while chlorpheniramine (50 mg/kg; ip), another H1-receptor antagonist, produced a non-significant degree of changes in the cycle. Drugs were administered at proestrus (P) oestrus (E), metoestrus (M) and dioestrus (D) of the cycle. Older rats exhibited more cycling irregularities than the younger ones when they were injected with histamine. These results suggest that histamine could play a role in reproduction as higher levels of histamine may be liable to cause adverse changes or damage to the clock mechanism (suprachiasmatic nucleus) controlling the gonadotrophin secretion and thus affect the reproductive functions. Key Words: Effect of histamine, oestrous cycle, rat. Résumé L'administration intracerebroventriculaire(ICV) de l'histamine(80-120mg)chez les “wistar rats” s'est avérée induire des cycle irreguliers et par moment des cycle œstru persistant quand administré à different stades du cycle. La cimetidine(50mg/kg),un recepteur-H2 antagoniste administre par voie intrapéritoneal(ip)générait un changement transitoire dans le cycle qui retournait a son rythme normal un ou deux jours après. La Tripolidine(50mg/kg,ip) un recepteur H1 antagonist ne montrait aucun changement dans le cycle œstral alors que le chlorpheniramine(50mg/kg,ip) un autre recepteur H1 Antagonist produisait un degrée de changement non significatif dans le cycle. Les médicaments ont été administrés à des périodes proœstral œstral, metaœstral et diœstral du cycle. Les souris les plus agées exhibère plus d'irrégularité dans leur cycle que les jeunes quand elles étaient injecter a l'histamine. Ces resultants sugèrent que l'histamine peut jouer un rôle dans la reproduction puisque des dose élevées peuvent causer des changement adverses.ou des degats au mechanisme de l'horloge interne(suprachiasmatique) qui contrôle la sécretion des gonadotrophines. Et ce sur la reproduction. Mot clés: effet histaminique, cycle œstrus, souris West Afr. J. Pharmacol. Drug Res. Vol.19 (1&2) 2003: 47-5

Saponins are involved in the analgesic and anti-inflammatory properties of Ficus platyphylla stem bark

The analgesic and anti-inflammatory properties of saponins (FPS) from the methanol extract of Ficus platyphylla stem bark were studied in rodents. FPS significantly attenuated acetic acid-induced writhes in mice and inhibited responses in both phases I & II of formalin-induced nociception. FPS demonstrated significant antinociceptive activity in Analgesy-meter model of nociception and significantly attenuated albumin-induced oedema in rats. Morphine significantly (

Annals of Experimental Biology 2014, 2 (4):21-27 Anti-inflammatory, antipyretic and antinociceptive activities of Orally Administered Aqueous Extract of Carica papaya Seeds in Animal Models

ABSTRACT It is generally agreed that medicinal plants and their products are safer than their synthetic counterpart

Real-time genomic investigation underlying the public health response to a Shiga toxin-producing Escherichia coli O26:H11 outbreak in a nursery

Shiga toxin-producing Escherichia coli (STEC) is a significant cause of gastrointestinal infection and the haemolytic-uremic syndrome (HUS). STEC outbreaks are commonly associated with food but animal contact is increasingly being implicated in its transmission. We report an outbreak of STEC affecting young infants at a nursery in a rural community (three HUS cases, one definite case, one probable case, three possible cases and five carriers, based on the combination of clinical, epidemiological and laboratory data) identified using culture-based and molecular techniques. The investigation identified repeated animal contact (animal farming and petting) as a likely source of STEC introduction followed by horizontal transmission. Whole genome sequencing (WGS) was used for real-time investigation of the incident and revealed a unique strain of STEC O26:H11 carrying stx2a and intimin. Following a public health intervention, no additional cases have occurred. This is the first STEC outbreak reported from Israel. WGS proved as a useful tool for rapid laboratory characterization and typing of the outbreak strain and informed the public health response at an early stage of this unusual outbreak