Skin hyperpigmentation disorders due to abnormal melanin production induced by ultraviolet (UV) irradiation are both a clinical and cosmetic problem. UV irradiation stimulates melanin production in melanocytes by increasing intracellular cAMP. Expression of heat shock proteins (HSPs), especially HSP70, is induced by various stressors, including UV irradiation, to provide cellular resistance to ...

Elevation in cell cAMP content can inhibit mitogenic signaling in cultured human airway smooth muscle (HASM) cells. We studied the effects of the type 3-selective phosphodiesterase inhibitor siguazodan, the type 4-selective phosphodiesterase inhibitor rolipram, and the nonselective inhibitor 3-isobutyl-1-methylxanthine (IBMX) on proliferation of cultured HASM cells. At concentrations selective ...

Adenosine, at concentrations ranging from 5 to 100 microM, decreases the efficacy of transmission at the perforant path synapses on dentate granule cells. We have used whole cell recording from these cells in slices to determine the mechanism of the reduced synaptic strength. We find that size of miniature excitatory postsynaptic currents (mepscs) is unaffected by adenosine at concentrations up...

Primary cultures of stromal-vascular (S-V) cells from adipose tissue were used to evaluate characteristics of preadipocytes from lean and preobese fetuses at several ages (50, 75, and 110 d). In insulin-supplemented (1 microM) cultures (serum free) there was a significant age x fetal genotype interaction (P less than .01) for glycerol-phosphate dehydrogenase specific activity (GPDH); GPDH activ...

Histamine H3 receptors modulate histamine synthesis, although little is known about the transduction mechanisms involved. To investigate this issue, we have used a preparation of rat brain cortical miniprisms in which histamine synthesis can be modulated by depolarization and by H3 receptor ligands. When the miniprisms were incubated in presence of forskolin, dibutyryl-cAMP, or 3-isobutyl-1-met...

Patch clamp experiments on dissociated olfactory sensory neurons Olfactory sensory neurons were dissociated from the olfactory epithelium of newts (Cynops pyrrhogaster) as described in [12, 13], salamanders (Ambystoma tigrinum) as in [7] or mice (BALB/c strain) as in [14]. All experiments were carried out in accordance with the Italian Guidelines for the Use of Laboratory Animals (Decreto Legis...

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-induced toxicity is particularly striking in adipose tissue, where it causes severe wasting. This phenomenon suggests that TCDD could have effects on adipocyte differentiation, now demonstrated using 3T3-L1 cells as a model system. When cells were treated with 10 nM TCDD before differentiation or during the first two days of induction in the presence o...

Sections of posterior intestine of the euryhaline killifish Fundulus heteroclitus adapted to sea water were stimulated by the calcium ionophore ionomycin (1 micromol l(-1)) in combination with agents to elevate intracellular cyclic AMP levels, 0.5 mmol l(-1) dibutyryl-cyclic AMP (db-cAMP) with 0.1 mmol l(-1) 3-isobutyl-1-methylxanthine (IBMX). Intestinal bag preparations from recently fed anima...

Introduction: To evaluate the cAMP -mediated IBMX (3-IsoButyle -1-Methyl Xanthin) and db-cAMP (dibutyryl cAMP) effects on differentiation of human Embryonic Stem Cells (hESCs) into nerve cells were the objectives of this study. Methods: We have used Royan H1 hESC- derived embryoid bodies with four treatment groups: six days treatment with IBMX (5×10 -4M) and db-cAMP (10 -9M) (referred to as...