Calcium Channels

BACKGROUND: Terminalia chebula Retz is traditionally used to relieve constipation. The current study was performed to investigate the pharmacological action of aqueous extract of Terminalia chebula seeds (ATC) in vitro and in vivo. METHODS: Terminal pieces of rat ileum were suspended in organ bath containing Tyrode solution. The ileum spontaneous motility frequency and contractility were recorded isotonically. To induce ileal contraction, carbachol and ATC were added to the organ bath.

Both poikilotherms and homeotherms live longer at lower body temperatures, highlighting a general role of temperature reduction in lifespan extension. However, the underlying mechanisms remain unclear. One prominent model is that cold temperatures reduce the rate of chemical reactions, thereby slowing the rate of aging. This view suggests that cold-dependent lifespan extension is simply a passive thermodynamic process. Here, we challenge this view in C. elegans by showing that genetic programs actively promote longevity at cold temperatures.

SUMMARY: The contractile function of the heart requires the release of Ca(2+) from intracellular Ca(2+) stores in the sarcoplasmic reticulum (SR) of cardiac muscle cells. The efficacy of Ca(2+) release depends on the amount of Ca(2+) loaded into the Ca(2+) store and the way in which this 'Ca(2+) load' influences the activity of the cardiac ryanodine receptor Ca(2+) release channel (RyR2).

Calcium acts as a second messenger and plays a crucial role in signaling pathways involved in cell proliferation. Recently, calcium channels related to calcium influx into the cytosol of epithelial cells have attracted attention as a cancer therapy target. Of these calcium channels, TRPV6 is overexpressed in prostate cancer and is considered an important molecule in the process of metastasis. However, its exact role and mechanism is unclear. NUMB, well-known tumor suppressor gene, is a novel interacting partner of TRPV6.

Our study examined whether calcium channels are involved in the anesthetic action of dexmedetomidine (100-300 micrograms/kg), a highly selective alpha 2-adrenoceptor agonist. To investigate this, we studied the effects of verapamil (1.25 or 2.5 mg/kg), a calcium channel blocker, and BAY K8644 (0.5 or 1 mg/kg), a calcium channel agonist, on the hypnotic-anesthetic effect of dexmedetomidine in rats. Loss of the righting reflex was used to determine the presence of anesthesia, and its length in minutes was referred to as the duration of hypnosis.

Although general anesthetics were first used more than 160 years ago, their mechanisms have remained mysterious. During the past decade, significant progress in our understanding of general anesthetic action at the cellular and network system levels has been made.

Recent clinical data support the clinical use of oral lavender oil in patients suffering from subsyndromal anxiety. We identified the molecular mechanism of action that will alter the perception of lavender oil as a nonspecific ingredient of aromatherapy to a potent anxiolytic inhibiting voltage dependent calcium channels (VOCCs) as highly selective drug target.

Acidification, which occurs in some pathological conditions, such as ischemia and hypoxia often induces neurotoxicity. The activation of acid-sensing ion channels (ASICs), which are highly permeable to calcium, has been considered the main target responsible for calcium overload in ischemic/hypoxic brain. However, the influence of extracellular proton on GABAergic synaptic transmission is not well understood.

Massage, one form of physical therapy, is widely used for a large number of musculoskeletal disorders, but its exact mechanism still remains to be elucidated. One hypothesis is that the shear stress caused by massage may induce cutaneous mast cells to release histamine, thereby improving the local tissue microcirculation of blood. In the present work, a mast cell line (rat basophilic leukemia cells, RBL-2H3) was used in vitro to study cellular responses to the stimulus of shear stress generated by a rotating rotor in a cell dish.

BACKGROUND: "Teucrium polium L." (TP) has been long recommended in Iranian folk medicine for its anti-diabetic activities. We attempt here to evaluate the effect of TP extract on insulin secretion in rat pancreas. METHODS: Rat pancreas was isolated in situ and perfused with Krebs solution containing low glucose (LG, 2.8 mM) or high glucose (HG, 16.7 mM) as perfusate. The aqueous extract (Aq. E) and methanolic extract (Met. E) of TP aerial parts and two partition fractions of Met. E were added to perfusate to evaluate insulin release.