Determination of β-adrenoceptors and cAMP in muscle from normal and splayleg Belgian Landrace pigs

-Adrenoceptors were identified and characterized by [³H]dihydroalprenolol ([³H]DHA) binding experiments in muscle membrane preparations from piglets. The [³H]DHA binding was rapid, reversible and stereoselective. Catecholamines competed for specific binding with a rank order of potency (-)-isopropylnoradrenaline > (-)-epinephrine » (-)-norepinephrine, indicating a -subtype of adrenoceptor. Saturation binding experiments with [³H]DHA showed no significant difference for either the number of binding sites or the equilibrium dissociation constants in normal and splayleg pigs.Adenylate cyclase assays indicated that the basal adenylate cyclase activity and the prostaglandin E₁ (PGE₁)-, (-)-isopropylnoradrenaline (ISO)-, 5-guanylyl-imidodiphosphate (GppNHp)- and sodium fluoride (NaF)-stimulated values were not significantly different in normal and splayleg pigs. In both groups, PGE₁ did not affect basal activity, whereas ISO and GppNHp stimulated adenylate cyclase activity significantly (p<0.001) to about 40% above basal level. NaF induced a significant (p<0.001) increase of cAMP in normal and splayleg pigs amounting to 48% and 61% respectively. Significant correlations between absolute adenylate cyclase responses to ISO (r=0.83^***), NaF (r=0.72^**) and GppNHp (r=0.61^*) and basal activity in the splayleg pigs were the most striking findings. In contrast, these correlations could not be detected in the normal pigs. Whether or not this observation reflects an alteration in the signal transduction system needs to be further investigated.To the best of our knowledge this is the first biochemical study which relates an altered -adrenoceptor function and porcine splayleg.     

Sensitivity towards DMI fungicides and haplotypic diversity of their CYP51 target in the Mycosphaerella graminicola population of Flanders

Journal of Plant Diseases and Protection - Septoria leaf blotch, caused by the fungus Mycosphaerella graminicola, is the most important wheat disease in Northwestern Europe, and is currently...     

Morphometric evaluation of myofibrillar hypoplasia in splayleg piglets

A morphometric method was applied to evaluate the EMS (extramyofibrillar space) in cross-sections of the musculus adductor as a parameter for the grading of the myofibrillar hypoplasia in splayleg piglets. Although there was a great variability between the individual piglets for the EMS values, a highly significant difference between normal and splayleg piglets was noted. Using this method it was found that myofibrillar hypoplasia indeed is associated with the splayleg syndrome.