Enkephalin convertase: localization to specific neuronal pathways.

نویسندگان

  • D R Lynch
  • S M Strittmatter
  • J C Venable
  • S H Snyder
چکیده

3H-Guanidinoethylmercaptosuccinic acid (GEMSA) selectively labels the carboxypeptidase B-like enzyme enkephalin convertase (EC) in rat brain tissue sections. We have used autoradiography with 3H-GEMSA to map membrane-bound EC in the rat forebrain and, in conjunction with lesioning techniques, to localize EC to specific neuronal pathways. The highest levels of EC are in the median eminence. High levels of EC also occur in the hypothalamic magnocellular nuclei, in several nuclei of the amygdala, the lateral septum, and the bed nuclei of the stria terminalis. Knife-cut lesions of the stria terminalis increase EC posterior to the lesion in the stria and deplete EC from the stria adjacent to the bed nucleus, suggesting that EC, like enkephalins, is axonally transported within the stria terminalis. Ibotenic acid lesions of the caudate nucleus destroy binding in the substantia nigra pars reticulata ipsilateral to the lesion, suggesting that nigral EC is associated with axons originating in the caudate nucleus. We have also mapped EC in detail in the hippocampus. EC levels are highest near pyramidal cells of CA 3-4 and the dentate gyrus granule cells. Quinolinic acid lesions destroy both the granule and pyramidal cells and destroy all of the 3H-GEMSA labeling except for a small amount in the molecular layer of the dentate gyrus. Selective destruction of CA 3-4 pyramidal cells with kainic acid eliminates EC in the pyramidal cell region. Destruction of granule cells of the dentate gyrus with colchicine depletes binding in the dentate gyrus without any change in the area surrounding field CA 3-4. High levels of 3H-GEMSA binding are present in the hippocampus at least 3 d before birth. These observations suggest that in the hippocampus the majority of EC is associated with pyramidal cells, which have not been shown to contain enkephalins. 3H-GEMSA autoradiography of the trigeminal ganglion localizes EC to the sensory neurons and not to white matter tracts there. These studies demonstrate that while EC is contained in enkephalinergic pathways, it is also present in some neurons that do not contain enkephalins.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Enkephalin convertase: purification and characterization of a specific enkephalin-synthesizing carboxypeptidase localized to adrenal chromaffin granules.

A specific carboxypeptidase that converts enkephalin precursors into enkephalin in adrenal chromaffin granules has been purified and characterized. In the adrenal this enzyme, designated enkephalin convertase, is uniquely localized to the chromaffin granules, which contain enkephalin and precursor peptides. Enkephalin convertase is markedly stimulated by CoCl2 and inhibited by EDTA or 1,10-phen...

متن کامل

Presynaptic versus postsynaptic localization of mu and delta opioid receptors in dorsal and ventral striatopallidal pathways.

Parallel studies have demonstrated that enkephalin release from nerve terminals in the pallidum (globus pallidus and ventral pallidum) can be modulated by locally applied opioid drugs. To investigate further the mechanisms underlying these opioid effects, the present study examined the presynaptic and postsynaptic localization of delta (DOR1) and mu (MOR1) opioid receptors in the dorsal and ven...

متن کامل

Gene expression of prohormone and proprotein convertases in the rat CNS: a comparative in situ hybridization analysis.

Posttranslational processing of proproteins and prohormones is an essential step in the formation of bioactive peptides, which is of particular importance in the nervous system. Following a long search for the enzymes responsible for protein precursor cleavage, a family of Kexin/subtilisin-like convertases known as PC1, PC2, and furin have recently been characterized in mammalian species. Their...

متن کامل

Presynaptic Versus Postsynaptic Localization of m and d Opioid Receptors in Dorsal and Ventral Striatopallidal Pathways

Parallel studies have demonstrated that enkephalin release from nerve terminals in the pallidum (globus pallidus and ventral pallidum) can be modulated by locally applied opioid drugs. To investigate further the mechanisms underlying these opioid effects, the present study examined the presynaptic and postsynaptic localization of d (DOR1) and m (MOR1) opioid receptors in the dorsal and ventral ...

متن کامل

Asymmetry of the endogenous opioid system in the human anterior cingulate: a putative molecular basis for lateralization of emotions and pain.

Lateralization of the processing of positive and negative emotions and pain suggests an asymmetric distribution of the neurotransmitter systems regulating these functions between the left and right brain hemispheres. By virtue of their ability to selectively mediate euphoria, dysphoria, and pain, the μ-, δ-, and κ-opioid receptors and their endogenous ligands may subserve these lateralized func...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • The Journal of neuroscience : the official journal of the Society for Neuroscience

دوره 6 6  شماره 

صفحات  -

تاریخ انتشار 1986