Calcium and caffeine interaction in increased calcium balance in ovariectomized rats

Abstract

OBJECTIVE: This study investigated the effects of caffeine intake associated with inadequate or adequate calcium intake in laparotomized or ovariectomized rats by means of the calcium balance. Forty adults Wistar rats were ovariectomized or laparotomized. METHODS: The animals (n=40) were randomly placed in eight groups receiving the AIN-93 diet with 100% or 50% of the recommended calcium intake with or without added caffeine (6mg/kg/day). The animals were kept in individuals metabolic cages at a temperature of 24°±2ºC, light/dark cycles of 12/12 hours, and deionized water available ad libitum. On the 8th week of the experiment, food consumption was measured and 24-hour urine and 4-day feces were collected to determine calcium balance [Balance=Ca intake-(Urinary Ca+Fecal Ca)]. RESULTS: Animals with adequate calcium intake presented higher balances and rates of calcium absorption and retention (p<0.05) than those with inadequate calcium intake, regardless of caffeine intake (p<0.05). Caffeine intake did not affect urinary calcium excretion but increased balance (p<0.05) in the groups with adequate calcium intake. CONCLUSION: Adequate calcium intake attenuated the negative effects of estrogen deficiency and improved calcium balance even in the presence of caffeine.

Aerobic exercise attenuates the effects of ovariectomy and sedentarism on body composition and food intake in female rats

“…The absence of estrogen after OVX should stimulate less vitamin D release, reduce the efficiency of intestinal calcium absorption and promote a negative calcium balance. Consequently, a reduced retention and lower bone calcium levels would be expected [1,21]. In addition to the negative calcium balance, OVX can also interfere with the homeostasis of other minerals, such as magnesium, zinc and phosphorus.…”

“…In the 23 rd week of life, the rats were submitted to Ovariectomy (OVX) or laparotomy (Sham) surgery. The animals were previously anesthetized with intramuscular ketamine (70mg/kg) and intramuscular xylazine (8mg/kg), receiving subcutaneous administration of the anti-inflammatory substance Ketofen: 2mg/kg/3d and antibiotic (sodium ampicillin: 30mg/kg) kg/5d) [20,21]. After 3 weeks of recovery, the animals were allocated into 4 groups (n=10), in a 2x2 factorial design: SHAM Sedentary (SS), SHAM Exercised (SE), OVX Sedentary (OS) e OVX Exercised (OE).…”

Interaction of drugs and coffee

“…Кросс-секционное исследование, проведенное на 330 добровольцах мужского и женского пола в возрасте 11-14 лет, показало, что уровень витамина D в крови значительно повышен у тех, кто потреблял 9-12 чашек кофе в неделю [31]. Когда рецепторы витамина D подавлены, концентрация витамина D в крови увеличивается, а, следовательно, абсорбция кальция остеобластами будет снижаться [32][33][34]. Поскольку витамин D регулирует процесс усвоения кальция, что играет ключевую роль в нормальном формировании костей и зубов, наблюдаемые изменения могут вызвать снижение минеральной плотности костей и повышение риска развития остеопороза [31][32][33][34], что особенно актуально для лиц пожилого и старческого возраста, поскольку у них наблюдается меньшее количество рецепторов к витамину D по сравнению с лицами более молодого возраста [31].…”

<p>Efek konsumsi kopi arabika selama masa laktasi pada tikus Wistar terhadap erupsi gigi anak tikus</p><p>The effect of Arabica coffee consumption during lactation of breastfeeding Wistar rats on the tooth eruption of the offsprings</p>

“…Penelitian membuktikan bahwa kopi dengan dosis tinggi (lebih dari 300mg) dapat menyebabkan peningkatan volume urine, pengeluaran kalsium dari intraseluler, dan penurunan absorpsi kalsium di usus. 23,24,25 Pengeluaran kalsium dari intraseluler tersebut dapat mengakibatkan meningkatnya kontraksi otot, salah satunya otot polos kandung kemih. 23,26,27 Saat tidak terjadi kontraksi, retikulum sarkoplasma mengakumulasi kalsium yang lebih tinggi dari rata-rata yang ada di sitosol.…”

“…23,24,25 Pengeluaran kalsium dari intraseluler tersebut dapat mengakibatkan meningkatnya kontraksi otot, salah satunya otot polos kandung kemih. 23,26,27 Saat tidak terjadi kontraksi, retikulum sarkoplasma mengakumulasi kalsium yang lebih tinggi dari rata-rata yang ada di sitosol. 26 Kalsium yang tersimpan dalam retikulum sarkoplasma akan keluar saat potensial aksi yang datang ke membran sel.…”