Check rotation of an obstacle

I've this code of an object that throws arrows: using UnityEngine; using System.Collections;

public class DispararFlechas : MonoBehaviour { public Transform Objeto; public float Seconds = 3; public GameObject DisparadorFlechas;

 void Start () {
     StartCoroutine(CoroutineShoot());
 }

 IEnumerator CoroutineShoot () {
     while (true) {
         Shoot();
         yield return new WaitForSeconds(Seconds);
     }
 }

 void Shoot () {
     Instantiate(Objeto, transform.position, Quaternion.identity);
 }

}

And this is the code of the arrows: using UnityEngine; using System.Collections;

public class Lanzamiento : MonoBehaviour {

 public float velocidadLanzamiento;
 // Use this for initialization
 void Start () {

 }
 // Update is called once per frame
 void Update () {
     //Checar la rotacion en z, dependiendo a donde vea, es el Vector3 que utiliza
     if(gameObject.transform.rotation.z == 90){
         //hacia arriba
         transform.Translate (new Vector3 (0, velocidadLanzamiento, 0));
     }else if (gameObject.transform.rotation.z == 270) {
         //hacia abajo
         transform.Translate (new Vector3 (0, velocidadLanzamiento*-1, 0));
     }else if(gameObject.transform.rotation.z == 180){
         //izquierda
         transform.Translate (new Vector3 (velocidadLanzamiento*-1, 0, 0));
     }else {
         //derecha
         transform.Translate (new Vector3 (velocidadLanzamiento, 0, 0));
     }
 }

 void OnBecameInvisible(){
     Destroy (gameObject);
 }

}

The problem I have is with the "if's", because I want that instead of checking the arrows rotation, I want to check the rotation of the object that throws them, and rotate the arrows depending on the rotation of the other object.

How can I do that?